Trans in limp, no alternator charging, what gives?

Charge it over night and see if the functions come back. Could still be a PCM.

Possibly bad alternator and that relay won't pick up. You could swap relays and see what happens. Check the voltage on the coil of the relay.
 
With jumper in place, trans doesn't limp
Click to expand...

Same thing happened to me. somehow I wasnt making a connection with the Prongs on the Relay. I got pliers and just bent the bottom and both outsid ones out a little bit to make it fit tight. Happened again the next night and did the same thing. If it continues then i'll just run a jumper in there permanantly.
 
PCM fix the problem?

Swap relays also. Could be marginal voltage and the relay won't pull in.
Do the grid heaters function still?
Lift pump cycling?
 
So the problem is diagnosed and fixed.. And the answer probably won't really help anyone else if they have this problem, because this kind of stupid crap only happens to me.

The short of it is, the wire that runs from the pcm, to the fuse box to the alternator, that gives a signal to charge, had some "cuts" in it INSIDE the wire loom.. It looked like it was just some wear on the wire's coating.

This in turn shorted out the computer which made it so that the POWER side of the computer no longer activated the positive side of the transmission relay or charging relay, IE no charge. (it also fried that single part of the PCM)

The new PCM I had is from a truck with anti-theft built into it, and those PCM's CANNOT be reflashed for use on another truck.

We basically taped up the damaged wire, then wired the relay to be kicked on by another key-on power-on circuit. Charging & trans works fine now.
 
I'm having this exact same problem with my 12V right now.

I even burned up the Blue wire. (Started smoking, even with key off.) I have a relay that turns the alternator on now.

My oil pressure gauge does not indicate oil pressure as well.

After doing some researching it seems the Oil pressure and the burned up blue wire might be in common with my trans starting in 3rd gear.

My trans starts in 3rd gear if I go over 30MPH.

My truck is manually shifted into O.D. as well as TCC lock-up being manually controlled by me. A few years back everything worked fine, except that the truck would not shift into O.D., so w it was wired up to be shifted manually.

IMO, I think I just need a resistor to keep my PCM from seeing to much trans pressure. The trans I have (1 week old) is setup for super high line pressure and super firm shifts. (It chirps the tires at 1/4 throttle on the 1-2 shift)

Merrick
 
check the wire on top of the trans that what happened to my dads when we thought it was the ecm.
 
You must log in or register to reply here.
Back
Top