B&W Ram

Once again, I'm not home until 10 PM, so no troubleshooting...I am without a garage, and have only a dark condo parking lot to use. As I'm also experiencing other odd problems now -- ie, the security system is activating intermittently (with the truck locked up) and the overdrive seems to be going in and out at highway speed -- I'm starting to suspect the ECM itself.

I will give the prior suggestions a try first -- as soon as I possibly can -- but I was wondering, in the meantime, if anyone on the board has replaced their own ECM. If so, I'd really like to read about it. Thanks for your time and your consideration.

PaulDaisy

Then I have to agree with Bent_valves - has to be a ground issue. With a bad ground the current finds all kinds of funny pathways instead of the normal ground return.
I strongly doubt that your ECM wold go so mad as to turning a bunch of unrelated circuits off and on. Especially your alarm system that is controlled by the timer module, IIRC. More likely, the ground connection comes and goes intermittently.

B&W Ram

It looks like I'll be working very late all week long, so I'm hoping to get time this weekend to work on the truck in the daylight. I will definitely take a close look at my grounds in the engine bay as soon as I can.

By the way, the overdrive symptom I described in my last post isn't the overdrive after all. I believe it's simply the engine power fluctuating somehow. Perhaps the signal going to the VP44 is erratic?

I certainly hope these problems are being caused by a ground loop somewhere under the hood...

B&W Ram

I wanted to give this plenty of time before actually closing the books on this problem. As hard as it is/was to believe, all of the problems I described in this thread were caused by the simplest possible issue: bad battery terminals. Yep, I was out in the weather tracing wiring (and wiring schematics) all over the place when the problem was simply a slight increase in DC resistance.

Lesson learned: If you're getting "phantom-like" electrical symptoms -- like an engine that won't shut down normally by the key/ignition switch --start out by testing your fuses and relays. If that doesn't solve your problem(s), do yourself a huge favor and replace both negative battery terminals.

Although my lugs seemed to be fairly tight, they were factory lugs that had been around since the middle of 1998. Yes, I had cleaned and treated all of my terminals regularly, but that doesn't mean that the lead I removed with my terminal cleaner/brush wasn't effecting the overall resistance in the battery circuit. I had to learn this the hard way, but there's a difference between clean and tight and "fairly tight." Just a minor increase in DC resistance in the battery circuit is all it takes to create a myriad of electrical issues. I really hope this helps someone in the future.

J.Suplanski

What about the fuel seleniod or the fuel seleniod relay, check the relay first its cheaper, i did have that problem a while back and that took care of the problem 1994 12 valve 2500 4X4 Keeps up with the traffic Thanks to Old Man Bob 4X4