tjohnson

I am trying to get the yellow indicator lights in the dash (ABS, low washer, 4WD, etc.) to work. I checked the fuse box in the cab, no burned fuses. I checked the relay box in the engine compartment, had no idea what I was looking for. I have owned this truck for less than a year, they have never worked. Shouldn't they cycle on each time I start the truck? Any help on where I might begin looking?

RustyJC

What year is the truck?

Rusty

tjohnson

1994

RustyJC

OK, the later trucks have a CANbus (controller area network bus) between the ECM (engine control module), PCM (powertrain control module), etc. The PCM controls the instrument module by sending outputs for the individual gauges and warning lights through the CANbus. On these later trucks, a function check is indeed part of the ignition on procedure.

Not sure how all this works on a 1994. My previous 1996 never had this type of problem, so I never bothered to figure out how its instrument module worked.

Rusty

tjohnson

Anyone else have a resource that might give a electrically-challenged guy some help on a 1994 whose yellow warning lights don't cycle on during startup?

infidel

Since they are all out it makes it somewhat simpler. My feeling is a bad ground, a connector not pushed together all the way or the wires pulled lose from a connector. Best thing to do is just start looking and jiggling wires.

tjohnson

Infidel,
Under the dash first? Engine compartment first? Give me your gut feeling on where to start and I'll start jiggling wires.

By the way, I am in the process of getting my parts gathered up for a fuel system overhaul in the week or so. I have recieved my overflow valve ($35) and a new lift pump ($95) from Marty Tompkins, my lift pump was still working but I thought now is the time, I'll keep the old one for a spare. Yesterday I ordered the WORKS for my heater/strainer assembly from Cummins ($110), is was completely shot. The thermostat on the top was burned up and the electrical connection to the heating element was burned up, it was covered with diesel fuel when I unplugged it so I am pretty sure it was sucking air into the fuel system through the pins and that's an explanation for my sputtering performance and clouds of white smoke when I start it up. I have got new fuel hose coming, it had to be ordered, no local access, and I am going all the way to the tank and eliminating the steel lines.

I truly appreciate all of you help, I'll let you know how the 1994 project is going. I know I have a lot to do, like KDP and exhaust (thinking about eliminating the cat and replacing the muffler, rest is solid), but one thing at a time. Guess I know where any extra cash is headed for a while!

Thanks again, Tim

infidel

Tim, my feeling is the problem is right behind the dash. Remove the knee bolster to get a good look. A ways back I was hunting down a dash electrical gremlin, the problem turned up to be in a place I would have never thought of, the ground wire to the ABS controller under the hood. It's a very small wire, easy to break and causes dash problems other than just the ABS.
Only way I even thought where to look there was with the aid of the factory service manual. Only about $50 for a '94 but worth it's weight in gold for electrical. Almost every different year Rams have quite a few electrical changes, a one book fits all years is often of little help.
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mishkaya

I'll second the advice for the repair manual as it has saved me much trouble as well. Sorry I can't be of any assistance for your current problems though.
Mishkaya