da_diesel

93 d350 auto w gear vendor...electrical problems no speedo ,a/c clutch,,not charging . not shifting into od

I just got this truck put a trans. in it & drove it home 200 miles. The next morning I drove it again no problems. But that evening I got all these symptoms so I started trouble shooting I found that I

Had no voltage going to cps
have voltage on all fusible links near driverside fender
have voltage across fuses
have power across all wires coming from the ignition switch accept one yellow wire on the end
no data coming from pcm
tested (test light to ground) the plug for the pcm with the pcm disconnected found only to wires that made a change when touched a blue w/yellow stripe and a blue with orange stripe. both seemed to activate the relays connecting to the a/c.
I havent done the vss test yet.

I would like to know

What wire should bring voltage to the pcm or what wires (if any) should be hot going into the pcm with the key in the run position?
Should I have voltage to any of the wires of my factory od switch?
Should the yellow wire on my ignition switch be hot?
Are there any other tests I should run before I put my new pcm on line?

simplysmn

Check your relay's on the driver's side fender well 1 controll's the air and I believe has something to do with other stuff also

Onemoparnut

Check the wiring for the cps it is known to wear where in turns over the edge of the head and goes down the front of the engine.

wannadiesel

Like Bill said, those are classic symptoms of a crank sensor problem. Check the wiring and the sensor gap before buying parts.

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da_diesel

Thanks guys I already bought the pcm and it was indeed burnt the question then and now is what burnt it.

I will check the wear on the cps wires
I had checked the relays. as suggested on the cumminsforum .I have a first gen 250 5spd and never had these issues .

I went ahead and put the pcm on today and all is working . I am hoping that I won't burn this pcm.

My goal is to eventually *89 this truck as I read some where that there is no pcm in a 89. I have a 518 transmission that shifts to od using the speedo . I 'd like to keep my speedo , but with everything else on individual circuits.

mopar2ya

crank sensor...or the dampner is coming apart and slipping. If the tach is dead and not charging, the only thing they share is a signal from the crank sensor..

j_martin

The two hot wires you found were probably the feeds to the air heater relays. There should be one power wire, red I think on with the key. Another should power up with the ASD relay.

What usually fries electronics is either a lightning strike, or a bad battery connection. Results are similar.

Welding on the truck without disconnecting the computer can cause problems.