I have a 92 D350 with a 5.9 cummins. Mechanically is rock solid with only 1.2 million miles but the electrical system is failing one system at a time. Does anyone have any schematics for it? it started with the radio. No real problem since I don't listen to it much. Then the overdrive power became eratic. It shifted when it wanted. Next the alternator quit and I had to bypass the ecm regulator circuit with an older external regulator .Now both the cruise control and speedometer have quit and the headlights sometimes flash off and on. Mostly the left one. the old beast runs too good to give up for a little electrical trouble.

 

I would get the maintenance manual from DC.............if you still have yer owners manual it will guide you to buying the maintenance manual I think on the last page

 

that is quite a milestone

 

It was previously owned by a family that worked for a carnival. The owners manual was long gone when we got it at an auction. About 900,000 miles of its life it towed a concession stand. Now we use it to haul scrap lead and finished lead diveing weights. 6000 pounds is a light load for it. I just hate digging into the wiring harness without a diagram to tell me where to start.

 

Not an owners manual - a Cummins service manual.

I have one for an 01 - but thats not going to work for you.

www.techauthority.com may have it - but that truck is getting pretty old and I dont know what kind of manuals they made for those first gen trucks. You might find something in Haynes or Chilton, but I wouldnt make any bets on that.

Sorry I cant be any more help.

 

Geno's Garage carries them.

Manual - 1992 DODGE FACTORY SERVICE MANUAL-Dodge Cummins Diesel Truck Accessories – Geno’s Garage
CD Version - 1992 DODGE FACTORY SERVICE CD-Dodge Cummins Diesel Truck Accessories – Geno’s Garage

Check teh body ground from teh battery to teh rad core support, mine got corroded and played all SORTS of electrical hell. It is kinda under sized also so you might just want to remove it, clean the spot on teh support were it attaches so you have shinny clean metal and put a new heavy gauge wire in its place.

 

also go to painless wire and get a new one to match the truck at a reasonable price just plusg right into place

 

The grounds are all good. I think it is in the main harness because someone in the past already bypassed a few wires around the engine harness plug. Probably because of corrosion. Chilton and Haynes manuals have no info in them about the diesel models, only the gas ones. I looked there first. I will try the Geno's Garage link and see if they can help. Thanks.

 

Can also give this a try, find out if the harness is plugged into the fire wall. If so, squirt it down with WD-40 (break down the corrosion on the pins), then blast it clean with brake parts cleaner. May or may not help, but it's worth a shot.

 

i had a simular problem on my 91. the idiot who owned it before me put a flatdeck on it and only twisted and electrical taped the connections. so it took me two days to re run all new wires under the dash, and to the back of the truck. but only at a cost of about 50$. i still have all the wiring diagrams i got when i researched the crap out of it. PM me your email, and ill scan them and email em to you.