My son just bought a 1995 Ram 3500 dually 4X4 V10. He had driven this truck last week and it ran great. The owner called him today, said it would not start and shot him an unbelievable price. He bought it. He could sell it for scrap and make money on it. So, we thought we would tinker with it.

I was hoping you guys could help us diagnose the issue.

With a spark checker we are not getting any spark from the coil pack to the plugs.

We have not found any blown fuses.

We swapped the ASD relay for the AC clutch relay and still no start.

The cam and crank sensor have 5 volts while cranking.

Any other ideas??

Thanks,

ND65

I've seen on the minvans (same coil packs IIRC) where way overdue spark plug/wire replacements have "backfired" through the coil and fried the ignition module. The module is part of the pcm.

Ptreey sure the v10 trucks are similar.

Heres the test part1: key on, coils unplugged from harness, test light clipped to battery negative, figure out which wire is keyed power to the coils. You'll likely have to cycle the key a few times while testing since they run through the asd relay. It will be one wire to each pack. No power? Check for power at the asd.
Part 2: key off, test light clipped to battery positive, coils unplugged. Probe the remaining wires at each coil, none should make the test light come on. If one does then that wire is shorted somewhere. Unplug pcm and see if short disappears, if so= fried pcm.

Thanks, ruderunner.

Is there an EZ way to check the PCM?

Follow the above, if the short to the coil goes away when the pcm is unplugged, the pcm is the short.
If you have wiring diagrams its easier to figure out which wires should or shouldn't have power.

ruderunner, we performed both tests you suggested. We found the power on both coil harnesses, and no light came on the other holes with the positive connected to the test light.

We did find the truck will fire when starter fluid is sprayed in the throttle body.

We checked the fuel pump and got anywhere from 34-38 lbs psi.

Anymore ideas?

Flaky crank sensor? Not Gettin a good signal when cranking but OK if the revs come up?
Cheap easy and common.

FIXED!!! It was the crank sensor. Thanks so much ruderunner.