Since this is somewhat on the topic I'll throw it in here and see if anyone has any ideas.

The wiring that goes down to my trans had been fried but only to the speed sensor and the OD plug. None of the other wires it the loom had been affected. What would cause these two plugs to burn? When I took the truck apart the speedo was workin but the OD wouldn't kick in. I don't even know where to start when it comes to trans stuff.

 

a short in the wire?

 

my 93 did the same thing i wound up replaceing the computer alternator & crank sensor once i did the comp it was all over with

 

Well damn that doesn't sound good! Anytime computer mentioned it seems like your dishing out $500 or better.

 

If you truck is still charging your computer is probably OK

 

Pewder...have you always owned the truck? Almost sounds like someone has applied a positive signal via a mystery switch to have control over the TC, not knowing any better, instead apllying a ground. The solenoid pack uses a constant positive as a common and switches ground. In any case, route out the bad wires, replace them, and see what it does. if you want, temporarily place a 2 amp fuse in the positive and two ground wires respectively just in case there IS a problem. As for the speed sensor...same deal. Route out the bad wires and try her again.

Levi....I agree with RSWORDS, to add to his suggestion, you could also run three temporary wires from the trans into the cab, then using a DMM (digital multi meter), see what the PCM is sending to the trans. Use the positive as a common and probe the negative's respectively for voltage and ee if the PCM is sending the signals. At this point, after checking that, use the same wires to try and gain manual control over the solenoids. You kill two birds with one stone. When done, remove you tee splices and wires, and let us know what happened. Good luck...

Chris

 

I just now joined and you guys are amazing. i am looking to buy another 93 cummins with an auto that wont shift into overdrive either. i am convinced to get it now. you guys are going to be my own personal "chilton" manual for my problems and modifications. Truly amazing!

 

99.9% of teh time its NOT the tranny...

 

Cummins Express, I just recently purchased the truck. Have not really done anything besides drive it from Las Vegas to St George (130 miles) and then around town very little. So I really don't know other than this damn thing leaked like a siv from ever place it could, thats what it seemed like. The wires are fried all the way down to the plug. So I would have to replace the plugs also.

Any one got a junk harness I can snag the wires from! ha ha

 

Ya my alternator is still charging butt my speedo and odometer dont work at all i will try the switch and see what happens and where is the computer on my truck i didnt think it had one