Help ASAP, wierd running truck

[85_305]

I'm no pro or anything, but ALL of the dash lights are pulsing during GP warm-up. Something is screwy.... main harness? Something is causing the main power of the truck to cut in/out.

Check batteries, grounds, power cables, engine grounds etc.

 

[907DAVE]

Thats the IDM relay clicking.

Check fuses #22 30A and #9 20A in the engine compartment fuse box. Make sure both show constant battery voltage with the key on.

If the fuses are OK, try jumping terminals 30 and 87 at the PCM power relay (relay right next to it, fender side) to bypass the relay and see if that makes any difference. If so, put a test light between terminals 85 and 86 with the key on to make sure it lights. If so, inspect and repair any terminal connection problems at the relay and try swapping the relay with a similar part to prove out a faulty relay.

 

[POWER-STRUCK]

Is there an obs powerstroke that doesn't use the OBD2 style DLC?

94.5-95 had an eec IV connector under the hood and the pcm had to be updated to make the obdII connector under the dash work.
I doubt that there is many left out there that has not beed updated.
they also have to be updated past 96 spec to read EOT pid

 

[Big Calo]

Thats the IDM relay clicking.

Check fuses #22 30A and #9 20A in the engine compartment fuse box. Make sure both show constant battery voltage with the key on.

If the fuses are OK, try jumping terminals 30 and 87 at the PCM power relay (relay right next to it, fender side) to bypass the relay and see if that makes any difference. If so, put a test light between terminals 85 and 86 with the key on to make sure it lights. If so, inspect and repair any terminal connection problems at the relay and try swapping the relay with a similar part to prove out a faulty relay.

Just talked to him, and it was fuse #9 that was blown, replaced it, and it fired right up, and purred away. Anything else we need to check, or is it just one of those random things?

Kinda funny thing, now I'm sitting on the side of the road with a locked up A/C compressor. The way life goes sometimes!

 

[ghohouston]

When I replaced my ipr pigtail not long ago, I accidentally touched the crimpers to the block, even thoug there was insulation on the wires, it grounded, and I had left my key on, idm relay started clicking, sure enough blew idm relay

 

[907DAVE]

That fuse powers the PCM, PCM relay, transmission, IPR and IDM.

A common location for a short is in the transmission connector or a solenoid itself. I would also take a peek at the IPR wiring and maybe check the IPR coil resistance.

 

[Big Calo]

Thanks, Dave!