pull

i have a 95 2500 4x4. with out warning my tach speedo od and ac die. i pull over shut it off and restart it, and it all comes back, it may do it again with in a mile or 200 miles. i put in a new crank speed sensor and got 5000 miles out of it, [about a month and a half of driving]. 1300 miles away from home it did it again. put a new speed sensor in and only got 1000 miles closer to home. pulled over restarted a few times with in 100 miles, then drove the last 200 with no problem.it doesn't matter if i'm pulling a trailer or not. any help would great, thanks

v8440

Starting to sound like either a bad pcm or a wiring fault somewhere between the sensor and the pcm. My vote is on a wiring fault. I've read that the part of the crank sensor wiring near the front of the cylinder head can chaff the wires, causing an intermittent connection. I'd check there first, then start tracing it through the harness. You may have to take a razor blade and cut open a bunch of electrical tape or plastic conduit.

One other possibility is a bad ground, particularly for the pcm. If the ground reference is lost for the crank sensor, the pcm won't be able to discern its signals from background noise. So, add ground leads and straps to your list of things to check.

pull

Thanks for the response. I checked and cleaned all wires and connections I could find from batteries to the rear diff., including all grounds. I think you may be right about a ground problem, some were a little dusty. It ran better from the start. I thought it ran fine before, but it has much more response now. Strange. I drove for 200 plus mile since, and no cut out problems, yet. Tomorrows another day. But it does feel better now. Yesterday I had to pull over and restart 7 or 8 times.

Lil Dog

By speed sensor and your reference to the differential do you mean you changed the sensor in the rear diff???

We are talking about the Engine Crank Sensor causing charging issues, not the VSS.

pull

The crank trigger sensor is what I replaced. I just mentioned the rear diff. as one of the many connections I checked and cleaned.That's all. The truck now has been running great for the last 350 miles. I'm convinced it was a ground problem. Problem solved? I hope.

Buckshotram

could it be the engine speed sensor?

pull

That's what I thought, but i replaced 2 within 6000 miles and it kept acting up. Still no problems since I cleaned all connections and grounds. It just flat out runs and shifts better than ever.

Lil Dog

Great to hear... Dodge and grounding problems seem to go hand in hand. I had ground issues on my older rigs too.

Dave D(SK)

Was wondering if you have this problem beat, I am having similar problems with my 96 but haven't had any luck in solving yet. Do you have any idea which connection or ground may have been causing your problem? I have tried a different PCM, changed the crank sensor and gone through most connections and grounds but no success yet. Next step will be to open cable wraps and see if I find shorted wire or something.

Thanks
Dave D