glow plug circuit problemo

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glenlloyd
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glow plug circuit problemo

#1

Post by glenlloyd » 15 years ago

Hey all
I really don't think the glow plug system is working. I noticed when I got this car that the wiring for the heater plug system looked like it had been fooled with, and after experiencing some poor starts when it was cold I just can't believe that the wiring has been reinstalled properly.

I can't post a picture, because I left my laptop's swappable diskette drive back in Iowa City and my camera, albeit old, only saves to diskettes. But, I can somewhat describe to you what I believe the problem to be.

There is a loom coming from the driver side firewall, it contains three wires, one green, one black, and one white. The white is connected to one of the glow plugs, the green appears to be grounded, and the black goes to a small fuse thingy that is mounted near to the 1st glow plug relay (according to the FSM) behind the fuel filter. Attached to the other side of this fuse thingy (it has two threaded posts) there is nothing...which has to be wrong. Now according to the FSM there should be two wires running the glow plug bus bar...right Al? This is where I have a problem..I think. I cannot believe that the black wire, which I believe comes from the glow plug timing box inside the car, connects to that post and then there's nothing else...it makes no sense

Any info would be greatly appreciated....

thanks
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!

Dr. Jones
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#2

Post by Dr. Jones » 15 years ago

It sounds like your 1st relay isn't hooked up the fused wire should be connected to that along with another white wire coming from the glow plug terminal. If you have a service manual there is a great section on troubleshooting this circuit in maintence section under trouble shooting "car won't start". Is it possible to be getting no heat at the plugs and the engine still start? Oh yeah you should be able to hear a loud click just after/before? the glow plug light goes out this is your #1 relay.
'82 Maxima Sedan x2
'92 Saab 9000 Griffin Edition Wrecked
'80 Ford E100(twisted tranny) SCRAPPED

glenlloyd
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#3

Post by glenlloyd » 15 years ago

Dr. Jones wrote:It sounds like your 1st relay isn't hooked up the fused wire should be connected to that along with another white wire coming from the glow plug terminal. If you have a service manual there is a great section on troubleshooting this circuit in maintence section under trouble shooting "car won't start". Is it possible to be getting no heat at the plugs and the engine still start? Oh yeah you should be able to hear a loud click just after/before? the glow plug light goes out this is your #1 relay.
Thanks for the quick response. I do have the FSM, but wasn't confident that it was correct since I didn't have the second wire from the little fuse thing to the bus bar.

I'll check the section, but I was hoping to hear from someone else with a 1982 Maxima about their wiring situation. I didn't want to go connecting something that wasn't supposed to be connected. Please also clarify the following,

"...isn't hooked up the fused wire should be connected to that along with another white wire coming from the glow plug terminal."

Can you be more specific....color, which wire...etc. The wires to the 1st glow plug relay are intact, and attached, it's this fuse thing, and what isn't attached to it that concerns me. I believe there should be a wire from the fuse thing to the bus bar...is this correct?

Thanks for your help!

PS - yes, you can start a car without operating glow plugs, but it is difficult.

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

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

goglio704
Posts:726
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Location:East Tennessee

#4

Post by goglio704 » 15 years ago

Both my cars are 83's, but I do have the 81 diesel supplement and the schematic is almost identical to the 83 manual. The 83 has an additional fuse that the 81 doesn't. Never seen an 82 up close and personal, but if 81 and 83 are nearly identical I'd say 82 is too. After looking at my cars and the manuals the only piece I find near the fuel filter with two threaded posts is the #1 glow plug relay. It should have two heavy wires on the posts and a smaller wire which is the coil or solenoid wire. Near the relay on the back of the strut tower is a metal box about 3 inches square. This is the dropping resistor. It has two heavy wires going to it through a plastic plug. #2 glow plug relay is different type of relay with a plug in connector. It lives under a sheet metal bracket with several other relays just behind the battery. If you don't have three wires on the #1 glow plug relay you will not have the initial fast glow ciruit, but the after glow circuit may still be active. If this is the case the car would be very cold blooded indeed because the after glow circuit runs at reduced voltage which will reduce the heat output of the plugs. I'm an electrical tech by trade and I'll help if I can. Do you have a twelve volt test light or a multimeter? With the ignition off check for 12 volt power on the threaded post which has a wire on it. If there is 12 volt power there then the missing wire goes to the glow plug bus bar. If there is power on the side with the wire, check the other post. If it has power with the ignition off then the relay is shorted internally. This would drain the battery and probably cook the glow plugs - which could be why it has been disconnected. If the post without the wire has no power and the one with the wire does then you know the contacts aren't shorted. If you put 12 volt power on the small wire of the #1 glow plug relay you should get a healthy clunk and power should then be present on the stud with no wire. If everything checks out this far I would run a new wire from the stud with no wire to the glow plug bus bar and see what happens. Another test that is easy to do with a test light is this. Connect the alligator clip to 12 volt plus and touch the probe to the glow plug bus bar. If it lights then you know at least one glow plug is good. The same test can be done on each plug with the bus bar removed and this checks the individual plugs.
Matt B.

83 Maxima Sedan, LD28, 5 speed, white, 130k miles. My original Maxima.
83 Maxima Sedan converted from gasser, LD28, 5 speed, 2 tone blue, 230k miles
82 Maxima Sedan, LD28, 3 speed auto, 2 tone Gray/Silver, 140k miles
81 810 Sedan, LD28, 3 speed auto, rust, rust, and more rust!

2005 Jeep Liberty CRD

Dr. Jones
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#5

Post by Dr. Jones » 15 years ago

I don't think that you'll be doing much trouble shooting today, but if you want to wait I'll load some pictures later tonight. 1st relay wires bulleted contector brown, main posts white and white w/black stripe(top) ran from below and to the right of the battery(connector) and then to terminal bus.
'82 Maxima Sedan x2
'92 Saab 9000 Griffin Edition Wrecked
'80 Ford E100(twisted tranny) SCRAPPED

glenlloyd
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#6

Post by glenlloyd » 15 years ago

Merry Christmas all

I did do some work on this on Thursday and found that the mysterious connections under the hood (one to bus bar, one to two post fuse thingy, third wire to ground) actually go to a mysterious and unknown chrome push button on the dash that I have never been able to figure out what it does. It's shown in the owners manual but not labeled or discussed, and I always wondered what it was.

Anyway, the two glow plug heater connections to the bus bar are present, but they were mounted back on the rearmost glowplug so I didn't readily see them, but they are there. The dash pushbutton switch I mentioned in the last paragraph was also wired to the bus bar so I disconnected it just in case it was causing a problem

I pulled and checked four of the six glow plugs and found them to be good. What I think the problem could be is with the relay itself or with the control box. Even when it was extremely cold the dash light didn't illuminate for more than say 4-5 seconds, which seems odd. Especially since the car was very cold.

The first thing I'm doing is replacing the rather questionable aluminum bus bar with a heavy copper cable. The aluminum bar is not in good condition where it attaches. After that I'll have to get in and diagnose the complete circuit to see where the problem is. It just doesn't start the way it should.

Thanks for all your help!

sa
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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asavage
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#7

Post by asavage » 15 years ago

glenlloyd wrote:. . . found that the mysterious connections under the hood (one to bus bar, one to two post fuse thingy, third wire to ground) actually go to a mysterious and unknown chrome push button on the dash that I have never been able to figure out what it does. It's shown in the owners manual but not labeled or discussed, and I always wondered what it was.
I have no idea what this is. It's shown the Owner's Manual, you say?
Even when it was extremely cold the dash light didn't illuminate for more than say 4-5 seconds, which seems odd. Especially since the car was very cold.
Four seconds is about right for 60 deg. weather. If it's much below that, ten to fifteen seconds is more usual. So, yes, there's a problem. But ignore the dash light and listen for the relay -- the noise will seem to come from the glovebox area. Wait for the "clunk". How many seconds?

The fast glow controller is pretty dependable on the Maxima. I've never heard of confirmed bad one. However, the temp sensor may run out of spec -- it's on the thermostat housing, IIRC.

I'm a long way from home, and I didn't drive the Maxima nor do I have access to the FSMs here, so I won't guess as to the wiring issues you seem to be having right now.
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.

glenlloyd
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#8

Post by glenlloyd » 15 years ago

asavage wrote:I have no idea what this is. It's shown the Owner's Manual, you say?
It's a small chrome push button, just to the left of the dash light rheostat and to the right of the small cubby on the left side of the steering column. I will find my owners manual and see if I can scan the dash page and circle it. At first I was sure this was an "add-on" item but then when I saw it in the manual I didn't think much about it. Now, based on the fact that the wiring comes out of a grommet on the drivers side of the cowl I'm wondering if it is after market or factory. Anyway, it's unhooked now!
asavage wrote:Four seconds is about right for 60 deg. weather. If it's much below that, ten to fifteen seconds is more usual. So, yes, there's a problem. But ignore the dash light and listen for the relay -- the noise will seem to come from the glovebox area. Wait for the "clunk". How many seconds?
I have noticed the clunk, and it seems to follow the dash lamp by a few seconds, but not any more than that. I need to do some electrical diagnostic work on this, unfortunately the weather aint so great!
asavage wrote:The fast glow controller is pretty dependable on the Maxima. I've never heard of confirmed bad one. However, the temp sensor may run out of spec -- it's on the thermostat housing, IIRC.
I'll check the temperature sensor to see what's going on.
asavage wrote:I'm a long way from home, and I didn't drive the Maxima nor do I have access to the FSMs here, so I won't guess as to the wiring issues you seem to be having right now.
I have my FSM but apparently there now isn't any problem with the glow plug wiring, other than the unknown wiring leading to the dash button. Maybe it's for the passenger seat ejector!

Thanks all

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
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Location:Des Moines, Iowa
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#9

Post by glenlloyd » 15 years ago

Here's a picture of the wiring that leads to the chrome button. I apologize for the size of the image, I'm without photoshop so I can't do much. I'll fix it when I get back home tomorrow.

The three sheathed wires lead in through a grommet in the drivers side of the cowl. The black wire is attached to one post on the fuse thing, with nothing else attached to the other. The green wire is grounded and the white (or yellow) wire was attached to the bus bar for the glow plugs. Before I indicated that this was the only wire, but in reality the other two were there, just now readily visible because of where the harness is located. Once I began to remove the bus bar I found the other two connections.

sa

http://members.isp01.net/addys/wiring2.JPG (edit 18May2013: link dead)
97 Jetta TDI, 86 VW Golf D
89 VW Fox diesel, 92 MB 300SD W140

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

goglio704
Posts:726
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Location:East Tennessee

#10

Post by goglio704 » 15 years ago

Looks to me like the previous owner had some kind of brain fart. I don't think this is factory. If you look at the black sheath of the wire I'll bet you find markings like "14/3 SJO" - looks like a piece of extension cord to me. Maybe an attempt at manual control of the glow plugs? I agree with the other posts about ignoring the glow plug light. I listen for the clunk of the #1 relay dropping out before I crank the motor. If I don't have success pretty quick I'll cycle the key off and back on trying to get another cycle of the #1 relay. Did you get you're other two plugs checked? Even one plug not heating could really slow you down.
Matt B.

83 Maxima Sedan, LD28, 5 speed, white, 130k miles. My original Maxima.
83 Maxima Sedan converted from gasser, LD28, 5 speed, 2 tone blue, 230k miles
82 Maxima Sedan, LD28, 3 speed auto, 2 tone Gray/Silver, 140k miles
81 810 Sedan, LD28, 3 speed auto, rust, rust, and more rust!

2005 Jeep Liberty CRD

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asavage
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#11

Post by asavage » 15 years ago

What Matt said, plus:

Yeah, that looks like a std extension cord to me. It once powered the Glow Relay #1, back when that "fusey thingy" (which is a std aftermarket circuit breaker, BTW) had power to the other terminal.

The wire going to the glow plug bus bar was likely to run a light up at the dash end, to let you know when the glow plugs were actually powered up. This is a mod I am definitely doing to my own, have had it planned for a couple of years, but I don't drive mine much. The relay clunking is good enough for a cold start.

I am having trouble starting up at "warm start" times. It starts fine cold, it starts fine hot, but if it's sat for 20-30 minutes, it requires a lot of cranking and then I get much smoke. For a test, I jumpered the glow relay with a warm engine for a few seconds, and it fired right up. I've replaced the slightly-out-of-spec temp sensor (new ones are still available from Nissan) and that didn't make the symptom change. I'm not sure what's going on, and I'm not automatically implicating the glow control system, because I'm running an alternate fuel (B100) and also have a leaking IP. I've switched back to petrodiesel as a test, and that also had no effect on warm starts, so I don't think the B100 is a problem, but it's possible (for example) that I'm getting air into the IP during warm shutdown -- this would explain the symptom.

However, I think I may try a manual glow plug button as a test. If that "fixes" the warm startup problem, I may swap out the Fast Glow controller and see if that makes a change.

I just mention all this in case any of this rings a bell.

Meanwhile . . . your button is almost certainly a mod. Not a bad idea, IMO, and you may want to reconnect the circuit breaker to a power source, and see if you can figure you what the other end of the wire that's connected to the bus; if it's disconnected, hook it to a cheap (under $3 at Radio Shack) 12v lamp and you'll have good feedback as to the current state of the glow plug system.
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.

glenlloyd
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#12

Post by glenlloyd » 15 years ago

Thanks for all the advice, I'll be checking the water temp sensor when I get back, but wouldn't it also register a fault in the dash gauge reading or is there another water temp sensor somewhere else...if so I haven't found it.

Also, regarding the relay clunk. When I start cold the clunk follows the light by about 4 seconds, no more. If I key off and back on to the pre-heat position again the light goes out instantly followed instantly by another clunk, that tells me the relay kicks off again. If I follow this with a third cycle I get a longer heating but no more than the first and the clunk following in four seconds.

It will start, but it takes effort, and I have to push the peddle slightly or it won't stay running.

I'll follow the FSM trouble shooting procedure first and see if I can't get this resolved. I don't like problematic pre-heat systems, if they work properly the engine starts easy, if they don't work then it's always a struggle.

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

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

Dr. Jones
Posts:125
Joined:15 years ago
Location:Raleigh NC

#13

Post by Dr. Jones » 15 years ago

Sorry, I didn't post those pictures they were pretty poor. Keep me informed how your copper wire glow plug bar works, maybe it would be easier to trace the shape to a piece of sheet goods and cut it out with snips. I was looking through the FSM and their is a trouble shooting section in the electrical part with a pretty detailed schematic. Best of luck and tell me what you find because I'm having the same problem, but for whatever reason I'm starting to suspect the Cold Start Device.
'82 Maxima Sedan x2
'92 Saab 9000 Griffin Edition Wrecked
'80 Ford E100(twisted tranny) SCRAPPED

glenlloyd
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#14

Post by glenlloyd » 15 years ago

I'll keep you posted on the copper bus bar project, even do some pics. I picked up some of the parts for this tonight, so I'll be starting it shortly. My aluminum bus bar just isn't in good shape.

I haven't isolated the problem yet because the car wasn't cold today when I went to check the resistance at the water temp sensor. I did manage to find out that the signal for the gauge cluster comes from a thermal transmitter that's located next to the water temp sensor.

I suspect that the sensor is the problem, but I won't know for certain until I take a reading in a little while.

BTW, the button in the car, on the dash, is shown in the owners manual, but it isn't identified. It is however clearly the same button. I am still not claiming that it's OE, but it's odd that what's shown in the manual is the same as that in the car...very odd.

SA
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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asavage
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#15

Post by asavage » 15 years ago

glenlloyd wrote:I did manage to find out that the signal for the gauge cluster comes from a thermal transmitter that's located next to the water temp sensor.
Yup, you got it.
glenlloyd wrote:I suspect that the sensor is the problem, but I won't know for certain until I take a reading in a little while.
If you want a "loaner", I've got two spares. One's already pulled.
glenlloyd wrote:BTW, the button in the car, on the dash, is shown in the owners manual, but it isn't identified. It is however clearly the same button. I am still not claiming that it's OE, but it's odd that what's shown in the manual is the same as that in the car...very odd.
I have a theory. I'm looking at the '83 Owner's Manual (because it's here, and the '82 is out in the car where it's raining like rain is going out of style, so hard that the wagon is literally in a lake of water right now!) and the "Instruments & Controls" page is 17. Number 6 is "Illumination control rheostat".
Image
(click on image for a larger version)
I'm betting that your button is just to the left of it. If so, what you're seeing in the illustration isn't a button but a raised area for an option that wasn't offered in the US. I'm guessing foglights or rear foglights (latter available in Europe on many cars). I guess I should buy that damned Canadian Maxima Owners Manual (in French!) that that guy on eBay has been trying to sell for six months -- but he wants a lot for it. I'm guessing that in the Canadian version, there may be a real control there.

But in the US version, there's nothing (IIRC).
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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