glow plug circuit problemo

Discuss (and cuss) the Nissan LD-series OHC Six diesel engine, popularly available in the US in 1981-83 Datsun/Nissan Maxima Sedans & Wagons.

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#46

Post by glenlloyd » 14 years ago

asavage wrote:
glenlloyd wrote:VW TDI's use both coolant system glow plugs and combustion chamber glow plugs
Aren't the coolant system plugs for cabin heat assist in stop-n-go traffic in very cold climes?
From the documentation I've read they are to help bring the engine to temperature as quickly as possible for EGR purposes. They aren't strictly for startup, but their significance isn't entirely clear either because they aren't on the auto-trans models. The only reference I've seen for them in the documentation is with regard to the EGR system, but it is very true that these engines cool down fast, and if you're stopped the engine temps drop.

They may be there for more than one reason too, but I wasn't aware that they cycled when engine temperature dropped. I do know that they are not integrated into the ECU such that if one fails you actually know it by virture of the check engine light (MIL).

My 97 TDI originated from Alabama and has the coolant heat plugs, but it, like all A3 and B4 TDI's, came only with manual transmission. I assume that all A3 and B4 (Passat) TDI's came with the coolant heat plugs because of the MT.

BTW, if one were looking to buy a TDI, the earlier A3 and B4 models appear to be less problematic than the later ones.

I'll check into this when I have a minute.

steve a
97 Jetta TDI, 86 VW Golf D
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#47

Post by davehoos » 14 years ago

the fuel is injected as a fine mist under hi pressure.if you pressurise things they heat up.the idea that the hot fuel in hot air will ignite.

the problem with prechamber is that it takes into the meatal and water the heat needed as it has a large surface area.[rough maths] a 2.2 liter engine needs 100 ml of prechambers-LD28 would be around 21 ml each..With the LD28 there is little going on in the piston at this time.unburnt fuel will atomise but a lot of wet fuel will lay in the chamber.the more wet fuel, the harder to start.

compression ratio.if you put a compression gauge on most engines you see that the first few few pumps are very low pressure.this pressure is needed to hold the rings onto the oil sealing them.when the piston is cold it is a lot smaller so there is less pressure.direct injection engines tend to fill the ring area with fuel helping to seal the engine.

diesel engines will run in the 5-8 :1 ratio areas.early diesel engines started on gasolene,warmed up using vapourised oil /kerosene then turned over to diesel.it is possible to change compression ratio with the engine running,in modern times a turbo/super charger is used.
hicompression is about fuel use eficency but oxides on nitrogen form in hot combustion,this is most toxic to humans.

.A large international bulldozer 1940's i looked at used a second petol motor the turnover the diesel engine with its exhaust heating an updraft vapourised oil tray.it had a downdraft petrol carby,and a heated intake manifold and fuel tank for running on kerosene.on the other side of the engine was full diesel set up the engine was side valve style,these are very low compression.
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asavage
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#48

Post by asavage » 14 years ago

davehoos wrote:early diesel engines started on gasolene,warmed up using vapourised oil /kerosene then turned over to diesel.

A large international bulldozer 1940's i looked at used a second petol motor the turnover the diesel engine with its exhaust heating an updraft vapourised oil tray.it had a downdraft petrol carby,and a heated intake manifold and fuel tank for running on kerosene.on the other side of the engine was full diesel set up the engine was side valve style,these are very low compression.
An example, from an old post of mine over at the biodieselnow.com forum.

=====================================================
willc733 wrote:
an ordinary gas engine will never fire on diesel? will it?
As an example: how easy is it to ignite BD if you splashed a puddle on the ground and threw a lit match on it?

This experiment illustrates that the volatility of BD is very low: it is hard to ignite at room temperature. Now imagine trying to vapourize BD in a cold engine, enough to ignite it with a spark. See the problem?

Many years ago -- WWII era and for a couple of decades afterward -- kerosene (similar to No. 1 diesel) was used to run various gasoline engines. For a number of years in the 60's, there were even kits to convert your Briggs & Stratton engine to kerosene operation. Kerosene (and diesel) are much cheaper to make, and therefore cheaper to sell than gasoline. Or, at least, they were back then. Refinery operations are now optimized for the proportion of output for each that are needed.

All the conversion kits I've seen did it the same way: start the engine on gasoline, and when it got good and warmed up, switch to the harder-to-ignite kerosene.

Kerosene has a lower octane rating than any gasoline, so the "kits" included either a shim or thick head gasket to lower the compression ratio, to avoid destroying the piston from preignition.

I suppose that it's possible to incorporate some kind of preheater to get the BD to vapourise and get it up closer to its flash point temperature, prior to admitting it to the combustion chamber, and you might be able to run a spark ignition engine with it. But SI engines require intake air throttling, which is a big efficiency killer ("pumping losses") -- and is one reason why modern-era diesels get better fuel mileage than a gasoline counterpart.

Offhand, I can't think of a good reason to want to do this.

PS No. 1: Incidentally, the MB 200D (and older -- possibly even the 220D) utilize an intake throttle for normal operation. It's the only diesel I know of that does this. The Nissan LD28 also uses an intake throttle, but it's under computer control to regulate EGR operation, not for normal user-controlled operation.]

PS No. 2: I once had a "diesel Toro lawnmower". Well, sorta.

I was renting a cheap storage barn-like structure in the '70s, and there was a beat-up '60s-era Toro walk-behind mower behind the barn. One summer day I decided that the area needed a good mowing/clearing, and the Toro was elected to Give Its All for the cause. I was able to persuade it to start and run one more time, though much aerosol light volatiles and select vulgar language was required. Removing the antique spark plug and heating its ground electrode cherry red didn't hurt, either.

Finally got it running (on gasoline) pretty good. It was a hot day. We dragged it about the building and surrounding overgrown garden for about an hour, and eventually got good and hot and sweaty, taking turns. After a bit, we ran out of gasoline, so we started pouring whatever smelled bad into the mower's tank. We went through paint thinner, some very old gasoline that smelled like an antique furniture restorer's back room, then some kerosene we found, and finally some diesel. The Toro really didn't cotton to this rough treatment, and protested with much clacking and rattling, but kept spinning 'round the by-now dull-as-a-two-by-four "blade". We kept knocking waist-high thistles down and mulching them, and in the normal course of events, the spark plug's wire got knocked off, was flying around the back of the deck. Didn't slow the engine down a whit.

I ran it about fifteen minutes in that mode, and finally nobody wanted to pull the Toro around anymore, so I killed the engine on a hillock to stop it. It never ran again, of course, but I can only assume that some glowing carbon or whatever in the combustion chamber was actually lighting off the somewhat volatile mess we were putting in its tank. I suppose that this was more of a "glow plug ignition" engine.

For most people, this sort of thing is a one-time-only experiment. It's certainly hard on lawnmowers ;)

[later post]
Dad:2-7-2000 wrote:
Re: Bucyrus Erie
> > era 1945
> >
> > Gasoline or Diesel ?
>
> This is _really_ weird! It sure looks like a diesel on
> one side, and it has a distributor on the other. Weird.

Well, ----- it was a loaded question.

It actually is ---> BOTH

The gas tank looks like it could hold about 1/2 gallon
The diesel tank looks like 15 / 20 gallons possibly

The idea is that you start it on gasoline and warm it up
and then switch over to diesel to use for loads.

While the injection pump has failed, it does start and will
move around ( I am told ) on gasoline, but does not have
enough power to do any work. It was driven to the
site you see in the three pictures -- in Alamo, NV

I thought you would appreciate this bit of trivia
part of the floral and fauna of Alamo

Image

Image

Image

Image

[later]
It was a possibility that I'd considered, but I was having trouble figuring out a compression ratio that would allow a diesel (min. 18:1, as far as I know) and a gas engine (max about 14:1) run with the same mechanicals. This sort of arrangement used to be fairly common for dual-fuel small engines in the east: start up on gasoline, switch over to kerosene, but in that case the compression has to be _lowered_ to work. B&S had a service bulletin about it, to install TWO head gaskets for proper operation.

> I thought you would appreciate this bit of trivia
> part of the floral and fauna of Alamo

I do! I like the hydraulic pump hanging off the front of the grillwork
<G>.
=====================================================
davehoos wrote:it is possible to change compression ratio with the engine running,in modern times a turbo/super charger is used.
Well . . . technically, changing the intake pressure isn't changing the compression ratio but the peak combustion pressure, but I know what you mean.

The early Lister diesel used a variable compression ratio system that involved a dual-seat valve, so that you could start it in high compression and lower it for normal running, just the opposite of what you do with a modern lawnmower or vintage BSA Victor 441 (etc.)! I've read that you could run in "high compression" mode for up to 1/3 load safely on that engine.
davehoos wrote:hicompression is about fuel use eficency but oxides on nitrogen form in hot combustion,this is most toxic to humans.
NOx isn't toxic at all, but it's a precursor to ground level ozone (O3, which isn't terribly good for you, despite many touted health benefits by some folks) and O3's a respiratory irritant IIRC. NOx also contributes to photochemical smog, which looks bad but isn't particulary dangerous in and of itself.

NOx without HC has no serious issues. The problem is that there's a lot of free HC around, and combine HC, NOx and sunlight and that's when you get O3. To my thinking, NOx control isn't as important as HC control. Diesels have very low HC emissions, which is why there were no HC & CO emissions tests for diesels for many years.
Last edited by asavage 13 years ago, edited 2 times in total.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
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philip
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#49

Post by philip » 13 years ago

Looks like I never did get a clear answer as to why IDI diesels are more dependent on glow plugs for successful cold starts than DI diesels.
davehoos wrote: The fuel is injected as a fine mist under hi pressure. if you pressurise things they heat up. the idea that the hot fuel in hot air will ignite.
When a gas is compressed suddenly, then heat is generated. However, when pressurized liquid fuel changes form (pressurized liquid to atomized spray), then COOLING occurs. The is what happens at the expansion valve in an air conditioning system. So you have cold, atomized fuel sprayed over the end of a glow plug that should measure about 950 degrees C (1550 degrees F).
davehoos wrote: The problem with prechamber is that it takes into the metal and water the heat needed as it has a large surface area.[rough maths] a 2.2 liter engine needs 100 ml of prechambers-LD28 would be around 21 ml each..With the LD28 there is little going on in the piston at this time.unburnt fuel will atomise but a lot of wet fuel will lay in the chamber.the more wet fuel, the harder to start.
Are not all the combustion chamber surfaces of a DI diesel just as cold at start up? Of course they are.
davehoos wrote: Compression ratio. if you put a compression gauge on most engines you see that the first few few pumps are very low pressure.
What you witness is a reflection of the schrader valve on the compression gauge adaptor AND the additional combustion chamber volume of the compression gauge hose.
davehoos wrote: When the piston is cold it is a lot smaller so there is less pressure.
How much is "a lot?" The piston skirt and ring lands do not aid in sealing compression. Do you know otherwise? Interesting, I've never seen blowby from a cold engine like I have from a hot engine.
davehoos wrote: Direct injection engines tend to fill the ring area with fuel helping to seal the engine.
How do you know this? With DI, fuel is directed into a deep combustion chamber (cup) milled into the piston crown. This design is NOT condusive to "filling the ring area" with fuel. In fact, having fuel (liquid or burnt) accumulating above the top compression ring RAISES exhaust emissions. If anything, the IDI design with its nearly flat piston crown is more prone to do this.

Image
Last edited by philip 13 years ago, edited 1 time in total.
-Philip
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#50

Post by Carimbo » 13 years ago

philip wrote:Looks like I never did get a clear answer as to why IDI diesels are more dependent on glow plugs for successful cold starts than DI diesels.
This from Chevron Products Diesel Fuels Technical Review, section 6, Diesel Engines DIRECT-INJECTION AND INDIRECT-INJECTION

"The more rapid mixing of fuel and air achieved in IDI engines comes at a price, however. The high velocity flow of air through the narrow passage connecting the main cylinder to the prechamber, as well as the vigorous swirling motion in the prechamber itself, causes the air to lose significantly more heat during compression than it does in a DI engine. Coupled with a pressure drop from the main chamber to the prechamber, this results in an air temperature in the prechamber after compression that is lower than that in a similar DI engine.

Since rapid fuel autoignition requires a certain air temperature, an IDI engine needs a higher compression ratio to achieve the desired air temperature in the prechamber. IDI engines operate at compression ratios of about 20:1 to 24:1; while DI engines operate at ratios of about 15:1 to 18:1. The heat losses that necessitate these higher compression ratios have another, more important effect: they decrease the efficiency of the engine. IDI engines typically achieve fuel efficiencies that are 10% to 20% lower, on a relative basis, than comparable DI engines.

Even with the higher compression ratios, IDI engines may still be hard to start. Most IDI engines use glow plugs to heat the air in the prechamber in order to make starting easier. Glow plugs, which are small resistive heaters, are usually powered for only the first few minutes of engine operation."

Is this telling us the IDI engine suffers greater air temp. loss, therefore causing harder starting?

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#51

Post by davehoos » 13 years ago

the idea that the hot fuel in hot air will ignite.

When a gas is compressed suddenly, then heat is generated. However, when pressurized liquid fuel changes form (pressurized liquid to atomized spray), then COOLING occurs. The is what happens at the expansion valve in an air conditioning system. So you have cold, atomized fuel sprayed over the end of a glow plug that should measure about 950 degrees C (1550 degrees F).


if you pour oil on hot steel it makes lots of smoke untill it reaches flash point,it needs an air mix at the correct ratio to get usable fire.there is not as much heat in the prechamber compared to the cylinder.the design of the prechamber is to mix the fuel with air forced throught the restriction port,the burning of the mix is mostly in the cyl.
in some engines the temps are extream at the prechamber port and valve head like insert is placed in the crown of the pistons.in some engines a glow plug in the intake heats low pressure fuel to be drawn in to the cyl but not burn in the manifold.

With DI, fuel is directed into a deep combustion chamber (cup) milled into the piston crown. This design is NOT condusive to "filling the ring area" with fuel. In fact, having fuel (liquid or burnt) accumulating above the top compression ring RAISES exhaust emissions. If anything, the IDI design with its nearly flat piston crown is more prone to do this.

when cold IDI engines are bad for unburnt fuel.in countries like australia little interest except for smoke emission was of concern untill now.a bad diesel is normally better than a petrol.i think IDI is more out of favour due to noise emisions.

some direct injection pistons are near flat.the design of the swirl chamber incresses the burn quality remeber that the combustion in a diesel takes place over a longer period than a petro and many new diesels are multi valve.
fuel in a cold cyl condences in most surfaces.if you doing lots of cranking to or have a miss fire,fuel with be found in the swirl chamber[combustion n the top of the cyl but it will be found coating the cyl walls and in the engine oil in the sump.this is refered to by oil companies diluted oil.engine rings do not seal metal to metal,they rely on oil.
lots of stationery engines use a small amoult of oil poured in on top of the intake valve[common practice with engine hat have been stored for some time]this is often just to help seal the rings and valves not add compression by reducing the size of the chamber.normal practise is to decompress the engine and wind the engine over untill parts are lubricated then DROP the valve lifter.DROPING early can brake the rings.

unburnt fuel is always pressent in the best engines.its measured in the exhaust as %Hydrocabon[HC].cold engines[even with lean mixtures] you will find fuel contamination,and as diesel evaporates at lower rates it will stay in the oil for some time.rotary engines with thier square cyl area are very good example of this,the fuel in the corners is difficult to burn.
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#52

Post by philip » 13 years ago

davehoos wrote:SNIP If you pour oil on hot steel it makes lots of smoke untill it reaches flash point,it needs an air mix at the correct ratio to get usable fire.there is not as much heat in the prechamber compared to the cylinder.the design of the prechamber is to mix the fuel with air forced throught the restriction port,the burning of the mix is mostly in the cyl. -SNIP- In some engines a glow plug in the intake heats low pressure fuel to be drawn in to the cyl but not burn in the manifold.
.
First, welcome back Dave. Haven't had a joust with you in quite some time. :wink:

Simply pouring oil over hot steel does not take into account the fuel atomization nor 450 psi compression nor secondary heat found in a diesel. Certainly such a crude air/fuel/heat mix is VERY rich by comparison but ... I get your idea. 'We' and Chevron agree to the notion that air traveling through the narrow passage connecting the combustion chamber to the prechamber results in a significant heat transfer from the compressing air to the passsage surface.

Regarding a "glow plug" in the intake. Give me an example of a diesel having "...a glow plug in the intake heats low pressure fuel to be drawn in to the cyl but not burn in the manifold." In diesel, pressurized fuel is injected into the combustion chamber ... not "drawn." And, fuel injection begins after the intake valve(s) is closed so ... the mixture cannot get into the manifold. We agree that once fuel ignition begins, pressure in the prechamber exceeds pressure in the cylinder hence the flame front and expanding gasses' movement into the cylinder which pushes the piston down.

Any electrically heated air intake system is not going to use a "glow plug" in the manifold. An electric matrix (screen) yes.
davehoos wrote:
philip wrote: With DI, fuel is directed into a deep combustion chamber (cup) milled into the piston crown. This design is NOT condusive to "filling the ring area" with fuel. In fact, having fuel (liquid or burnt) accumulating above the top compression ring RAISES exhaust emissions. If anything, the IDI design with its nearly flat piston crown is more prone to do this.
When cold, IDI engines are bad for unburnt fuel. In countries like Australia, little interest except for smoke emission was of concern until now. A bad diesel is normally better than a petrol. I think IDI is more out of favour due to noise emisions.
My research suggests combustion noise is much more of a problem with DI hence ... the persistance of IDI for many applications that are not highly concerned with exhaust emissions. DI chamber design simply has fewer nooks and crannies for incomplete combustion to occur but at the price of noise suppression.

So I put it to you, Dave; in spite of measures to offset compression generated heat losses in IDI (namely higher compression than in DI), what else makes IDI so much more dependent on getting IDI fired off in cold weather?
-Philip
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#53

Post by asavage » 13 years ago

philip wrote:Any electrically heated air intake system is not going to use a "glow plug" in the manifold. An electric matrix (screen) yes.
Some intake manifold heaters are a bit odd-shaped.

From July-79 "Onan Marine Training Manual", pg. 39:

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Last edited by asavage 7 years ago, edited 4 times in total.

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#54

Post by davehoos » 13 years ago

english.euro diesels are very common in this part of the world pre 90's.
i dont know as fact but i be suprised if the LD series engines wasnt designed or influenced by a company like perkins,the SD/TD range is a different design.you dont see these on cat/cummings/detroit type truck engines but on euro imports.

perkins designed engines-tractors often use extream cold start designs.
gas and liquid injection into the air intake often with some form of heating.
most tractors sold here copy most of these old ideas.

mazda diesels-are mostly of perkins design.these often use the heated diesel glow plug..it is conected to the waist return hose that conects to the injectors.they have the heated screen as well.

toyota landcruiser-recently sold engines here have the heated diesel vapour injector,japanese imported nissan safari TD42 often have a bung in the intake to take the toyota manifold heater.ive seen some with a blanked fuel hose tied to the wiring..the isuzi mark 1[gemini] has the same size heater without the fuel line.you see these on newer trucks.
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#55

Post by davehoos » 13 years ago

it just a guess.

new DI common rail engines are being sold here as quiet engines,they are lower compression.and have better constuction designs.the old designs have been difficult to pass our driveby noise requirements.

BUT all the written stuff i can find refer to noise reductions due to the timing of injection versus ignition points.this is not possible with the IDI design.if you google you see lots of references to pilot injection raising the compression just before the ignition starts to reduce ignition shock.

from my training and reading IDI engines have always been refered to here as high speed diesels.2 stoke engine are a true high speed design.improvement in DI designs have seen these reclaim that high speed tag.by high speed i refering to up to 5000 RPM, older truck engine often dont go over 2000.as with all high speed designs low speed performace is reduced. starting is below low speed.
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#56

Post by philip » 13 years ago

davehoos wrote:SNIP- Perkins designed engines-tractors often use extream cold start designs. Gas and liquid injection into the air intake often with some form of heating. Most tractors sold here copy most of these old ideas.
I am asking only; what (if any) electric air preheater is on these engines patterned after Perkins design.
davehoos wrote: Mazda diesels-are mostly of perkins design.these often use the heated diesel glow plug.it is conected to the waist return hose that conects to the injectors.they have the heated screen as well.


I understand having a heated screen (matrix) positioned to preheat air entering the intake air manifold. But of what value would it be to heat fuel leaving ('waste') the injectors?
-Philip
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#57

Post by philip » 13 years ago

davehoos wrote:it just a guess.

new DI common rail engines are being sold here as quiet engines,they are lower compression.and have better constuction designs.the old designs have been difficult to pass our driveby noise requirements.
By 'old design' do you mean previous DI or do refer to old IDI engines? There have been huge combustion noise reductions made using 'combustion rate shaping' fuel injection technology in DI diesels.
davehoos wrote:BUT all the written stuff i can find refer to noise reductions due to the timing of injection versus ignition points.this is not possible with the IDI design.if you google you see lots of references to pilot injection raising the compression just before the ignition starts to reduce ignition shock.
My point exactly. However, I see no reason combustion rate shaping technology could not be applied to ID diesels. That these high tech fuel systems have been fitted to ID diesels (overwhelmingly) is because ID design produces less NOx than IDI and ... according to "Carimbo's" Chevron article ... ID's open combustion chamber has superior fuel burning efficiency (which is not necessarily synonymous with superior MPG).
-Philip
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#58

Post by asavage » 13 years ago

Upthread, Steve showed us a custom glow plug bus that he fabricated.

http://members.isp01.net/addys/busbar2.jpg (edit 18May2013: link dead)

I liked the idea, so I put in an order for two of them :)

When working on my '83 Wagon a few months ago, I found this (click on any image for larger):
Image

Obviously, I can't get a good 100 ampere connection through that rotted aluminum, so I got out my Addy GP Bus, Rev A :

Image

With only minor bending, it can be installed without removing anything. But I ran into some clearance problems with Rev A. The worst was this one, near the hose connection adjacent to GP No. 5:

Image Image Image Image

I ended up bending the bus enough to gain some clearance, but I'm not entirely happy with it. Rev B will fit better.

In combination with some rewiring, the Wait light goes out before the relay drops out ("goes thunk"). Previously, the relay would drop out first, which I knew to be wrong.

=============================================

My GP Bus wiring modifications on this rig were required to eliminate some nasty wiring hack that occurred before I acquired it.

Image


On the stock system, there are two hefty-looking wires feeding the GP bus. But if you look at the wiring diagram ('83 FSM, page EL-40), you'll see that only one of them is feeding current from the GP Relay; the other is a voltage sense line back to the GP Controller ("Fast Glow Control Unit", "GPC"). So there's only one 10ga wire feeding current to the GP Bus on the engine.

And have you noticed the physical path that those wires take? From the GP Bus terminal, the pair goes through Connector 44M-10E, then they run forward on the engine, then across to the frame rail. The current feed wire then splits: one branch to the GP Relay 2 (afterglow) in the relays panel, the other to GP Relay 1 at the rear of the shock tower. The other White wire follows the latter path to the inline fuse taped to the harness up under the wiper motor (under blue tape).

I replaced both those wires, and the intervening Connector (44M/10E) that had been chopped up, making them about 1/3 as long. I chopped out Connector 44M-10E and cut those stock wires back to the harness wrap. Careful, as one of them will still be hot because it is still wired to GP Relay 2.

Upstream, in the OEM system, the feed from the battery to the GP Relays is spliced (wyed) inside the harness. One wire (from Connector 9M, fusible link at the battery, Wht/Blk) splits to two in the harness, to feed both relays. Similarly, the output of both relays siamese to the single wire that feeds the GP Bus -- the GP Relay 2 (afterglow) feeds through the big dropping resistor first.

The point is that both relays are wired in parallel, both input and output. And that a single wire feeds in, a single wire leads out of both.

Image Image
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Last edited by asavage 7 years ago, edited 5 times in total.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

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#59

Post by glenlloyd » 13 years ago

Al, Rev. B should be on its way to you on Monday. Hopefully all the kinks have been worked out although I wasn't able to test through install on my own car. The temp outside is just not conducive to this kind of thing and I have no (functional) garage as of yet.

steve a
97 Jetta TDI, 86 VW Golf D
89 VW Fox diesel, 92 MB 300SD W140

gir - won't the sploding hurt?
zim - silence!

glenlloyd
Posts: 640
Joined: 14 years ago
Location: Des Moines, Iowa
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bus bar rev B

#60

Post by glenlloyd » 13 years ago

Here's a photo of the revised bus bar. It fit on the jig but it needs to be mounted to the plugs yet to verify there aren't any clearance issues. Although the jig was built using the OE aluminum strap, I found a problem with the alignment at plug #4.

This was somewhat more complicated to manufacture. If it could be simplified it would be easier to construct. The clearance problems that make this difficult are the oil cooler top, the cooling system hose clamp and two head plugs further forward toward the front as well as a cooling hose with several clamps that sits below plugs 1, 2 and 3.

I'm still trying to determine whether this can be accomplished with a straight rod with zero bends. I'll know more later today.

http://members.isp01.net/addys/busbarrev2.jpg (edit 18May2013: link dead)

steve a
97 Jetta TDI, 86 VW Golf D
89 VW Fox diesel, 92 MB 300SD W140

gir - won't the sploding hurt?
zim - silence!

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