Wiring Butchered!! Need Help

Dealing with all subsystems specific to the diesel powered Datsun-Nissan 720 pickup trucks.

Moderators: plenzen, Nissan_Ranger

cseger1
Posts: 116
Joined: 14 years ago
Location: Houston TX

Wiring Butchered!! Need Help

#1

Post by cseger1 »

So I got my 81 SD22 powered 720 home and surveyed the damage. It is extensive. I have been reading through this board for three days and I think I am getting more comfotable with many of the concepts. This is my first diesel. One of the PO's was the worst mechanic of all time and had the truck for many years to hone his skills. Here are the highlights:

Every electrical circuit in the truck failed and was patched around (possibly by apes).


Image


Image

Image

There seems to be a TOW CHAIN holding the motor down on the left side motor mount.
Image

Image

The injection pump controller arm was removed and a cable was added to the cab for shutting down the motor. What happens to the IP if it sits termianlly in the run position?

Image




So far I got the truck home with the aid of a new battery and starter fluid. I put about 120 miles on it getting to this point. It ran great until this morning when it wouldn't start. The solenoid in the starter goes "click buzzzz". Shorting the starter at the solenoid produces the same result. At this point I decided to unbutcher it. With the aid of Al Savage's online manual I may stand a chance. Probably not before my wife kills me. Anyway, given the brief description and pictures I put up, what would y'all recomend?
Christian
1981 720 SD22
cseger1
Posts: 116
Joined: 14 years ago
Location: Houston TX

#2

Post by cseger1 »

And what should be plugged in here? I can't find the matching ends to these two. They are up near the firewall on the pass side.

Image
Christian
1981 720 SD22
User avatar
philip
Deceased
Posts: 1494
Joined: 15 years ago
Location: Southern California, USA

#3

Post by philip »

cseger1 wrote:And what should be plugged in here? I can't find the matching ends to these two. They are up near the firewall on the pass side.
First let me say that "butcher" ought to be deported just on principle.

On the battery + clamp, there is a fuseable link group. System, charging, glow plus, and more are protected here.

Image

The two plugs are for the missing DPC module. This module controls the Injection Pump Control mechanism under the Injection Pump (probably missing now?) DPC System

Image

There is no damage being done by leaving the Fuel Control Lever on the RUN position after the engine comes to a stop.

Image
Last edited by philip 14 years ago, edited 1 time in total.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
redmondjp
Posts: 204
Joined: 15 years ago
Location: Redmond, WA

#4

Post by redmondjp »

I'm 100% behind you for getting things back to stock. With that being said, however, there's nothing wrong with a well-implemented manual start system (as used on 1000s of diesel tractors over the decades), and you're pretty close to that now. Especially if you want to try to use the vehicle while you're rounding up the missing parts.

You would need to replace that 'pull-only' cable with a 'push-pull' one (try a marine parts place) such that you can get the IP control into the 'start' position. You could also install a second 'pull' cable but on the opposite side of the lever, to get into the 'start' position.

And a momentary pushbutton or toggle switch, controlling a heavy-duty 12V relay or solenoid for the glow plugs, will work just fine (although it won't have the after-glow capability which is definitely nice to have). I'm working with some 555 timer circuits at work right now, so I could come up with a delay circuit that would keep your glow plugs energised for X seconds after letting go of the switch, which would get you close. I can't tell if that switch you are showing is momentary or maintained--if maintained (meaning switch stays 'on' until you turn it off), I would definitely change that right away.

Just throwing some ideas out there . . .

from your pictures, I'd say that your truck had an IPCectomy and a fairly clean one at that--more surgeon-like than done by a butcher. All you have to do is reinstall the original parts and remove that cable. GPCectomy done too, although not as clean (it never is).
1982 Datsun 720 King Cab, SD22, 86K miles (sold)
1981 Rabbit LS 4-door, 1.6D, 130K miles (sold)
1996 Passat TDI 4-door sedan, 197K miles
cseger1
Posts: 116
Joined: 14 years ago
Location: Houston TX

#5

Post by cseger1 »

Any idea about the chain on the motor mount?
Christian
1981 720 SD22
User avatar
philip
Deceased
Posts: 1494
Joined: 15 years ago
Location: Southern California, USA

#6

Post by philip »

cseger1 wrote:Any idea about the chain on the motor mount?

Longitudinally mounted engines will torque away from the driver's side engine mount. In all likelyhood, the rubber is separated from the metal base which would permit the engine to lift up, pivoting up on the passenger side mount when letting the clutch out especially in 1st gear ... typical of slogging up dirt grades where traction is being gained and lost repeatedly. New mount needed. No doubt all that oil caused the mount failure.

Check also your driveshaft carrier bearing rubber support
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
ffdjm
Posts: 18
Joined: 15 years ago
Location: Fairbanks, Alaska

#7

Post by ffdjm »

The "click bzz" often means a bad connection in the cable from battery to starter. The next time you hear the click bzz check the cables for warm spots which indicate a bad connection and replace as needed. OEM starter cables on the SD22 eventually fail at the battery end due to excessive flexing. The usual fix is a the replacement terminal shown in your photo. These usually do not make a good connection. Replace the whole cable. The correct size seems to be 2. I used arctic welding cable to get good flexibility and crimp on terminals from a local shop that sold solar power supplies. And yes, I know this is overkill.

As long as your glow plugs work the engine will start without the pump controller being put in start position. The exception being very low temperatures, when manual control may be justifiable. The DPC motor is vulnerable to water; mine lasted until the first big rainstorm when I hit a puddle. I replaced it with a piece of thick cord from the dashboard to the pump to stop the engine. The glow plug controller is reliable. Mine has lasted 298k miles.

Douglas
User avatar
philip
Deceased
Posts: 1494
Joined: 15 years ago
Location: Southern California, USA

#8

Post by philip »

ffdjm wrote:The "click bzz" often means a bad connection in the cable from battery to starter. -SNIP
It's worth mentioning here that a major wiring harnass ground is crimped to the OEM battery negative cable about a foot away from the battery.

Take the time to wire brush the eyelet and to remove all the body paint around the body hole.

Harnass ground below battery

I still have both my original cables but I had to replace the positive clamp when I bought the truck.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
zen
Posts: 118
Joined: 15 years ago
Location: london uk

#9

Post by zen »

re the ip start/run/stop controller...

as stated a solid cable works fine...if no marine shops about you will find lots of cars use solid cables for the hood release..i use one from a land rover for example..

good luck.(espically with the wife!! :wink: :wink: )
turbo it

(sd33t home turbo set up if anyone is interested..)
cseger1
Posts: 116
Joined: 14 years ago
Location: Houston TX

#10

Post by cseger1 »

Update:

The first thing I did was clean all the connections from the battery wires. The one by the battery was painted and covered in dirt. Its bare and clean now.

Then I got new main cables and cleaned the starter's terminals. No help. Even shorting the starter had no effect. I decided a new starter would cure it. $77 from O'rielly rebuilt. The swap was way easier than I anticipated after reading the starter threads. The truck fired right up with the new starter.

I got a new fuel filter in it and changed the oil. She runs like a top now. She eats a LOT of oil though. I think its time for a ring job. How long does it take if you DIY and what would a shop charge?

Christian
Christian
1981 720 SD22
User avatar
asavage
Site Admin
Posts: 5369
Joined: 15 years ago
Location: Duvall, Wash.
Contact:

Re: Wiring Butchered!! Need Help

#11

Post by asavage »

cseger1 wrote:There seems to be a TOW CHAIN holding the motor down on the left side motor mount.
Image
There's a right-side '81-82 720 diesel motor mount on eBay right now for ($10 + 6).
Image
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.
cseger1
Posts: 116
Joined: 14 years ago
Location: Houston TX

#12

Post by cseger1 »

Thanks for the heads up. I saw it too, my chain mount is on the left side. In other news the charging system has failed. I haven't gotten a chance to trouble shoot but I think the alt. is FUBAR. Any good advice on running down problems with the alt? So far what I know is voltage is at 12.10 running or not. I have it on the battery tender now.
Christian
1981 720 SD22
User avatar
asavage
Site Admin
Posts: 5369
Joined: 15 years ago
Location: Duvall, Wash.
Contact:

#13

Post by asavage »

cseger1 wrote:I haven't gotten a chance to trouble shoot but I think the alt. is FUBAR. Any good advice on running down problems with the alt? So far what I know is voltage is at 12.10 running or not.
12.1v is way too low. Charged battery = ~12.6v, and running voltage must be above 13.5v minimum.

See my post on the SD22 alternator diode and VR problems, including info about the shaft seal that must be replaced if you open up this alternator (so buy it beforehand!). Unless you have been into a couple of alternators and are very comfortable doing quite a bit of soldering, I advise replacement of the entire assy.

However, brushes are easy to replace on this alternator, and can be done without removing the alternator (unless you have an A/C compressor above it), so naturally that would be the first place to look.

Sometimes you can get a good deal on a cheap rebuilt alternator from eBay.
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.
User avatar
philip
Deceased
Posts: 1494
Joined: 15 years ago
Location: Southern California, USA

#14

Post by philip »

cseger1 wrote:SNIP- Any good advice on running down problems with the alt? So far what I know is voltage is at 12.10 running or not. I have it on the battery tender now.
To Al's information I would add only that you confirm that all four fuseable link wires (2 green, 2 black) are conducting electricity (amperage), located off the positive battery clamp.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
cseger1
Posts: 116
Joined: 14 years ago
Location: Houston TX

#15

Post by cseger1 »

Fusible links are MIA. The 4 wires from the harness go direct to the pos. terminal via a spade connector and a wire nut. There is one wire going to the alt. from the pos. terminal as well. The whole thing is a huge mess. I have been thinking hard about getting one of those "Painless" wiring harnesses that they build for hot rods. It would be hugely labor intensive but at least I'd know what was what.

I got an ebay rebuilt alt. from a guy here in TX. Should be in tomorrow. I'll gove a report on what kind of shape its in when I get it.


My FSM came yesterday so I am happy about that.
Christian
1981 720 SD22
Post Reply

Who is online

Users browsing this forum: No registered users and 3 guests