'92 Dodge Cummins with no charge from the alternator
 

Hey guys,
Already posted this in the Dodge 1st gen section, figured I'd post it over here too. I'm getting no charge on the batteries. Tried replacing the voltage regulator, the crank position sensor, and the alternator. Still not getting a charge on the batteries, wondering what else I can do to test or try and get it fixed. Only other thing I can think of is the engine management computer thing. Thanks for any help you guys can give me.

I dunno how far this goes back if its on yer truck or not but my 01 has a battery temp sensor under the drivers side battery, if the battery is hot it wont charge no way

Mine does not have that sensor, but thanks for the idea.

Check the engine speed sensor (mounted by the harmonic balancer). Probably a little crud caked on it.

Already cleaned and adjusted that, still didn't work. Got a new one and replaced it, still doesn't charge. Replaced the alternator after that, still doesn't charge. Starting to wonder what's wrong with it and what can I test with my meter to eliminate things.

Obviously the battery is charged enough. Perhaps do a load test on it anyway??

With the truck on and running and the headlights on, voltage on the battery is 11.9, should be more like 13.8. Left the new alternator and crank sensor in and bypassed the voltage regulator section by shorting the field to ground, and the system did charge. So something isn't telling the alternator to charge, so at this point I've replace a $180 alternator and $120 crank sensor for no good reason. Seems that perhaps the computer or one of it's sensors that tells it to tell the alternator to charge isn't working properly. Anyone have any ideas of quirky stuff the the Powertrain Control Module might be looking for?

our 92 had the same thing happen. the problem is somewhere in the PCM circuit or wiring. I gave up on trying to diagnose the PCM and added an extermal electronic regulator. The same one used on dodge and chrysler for about 30 years. If you need help I can send information on how to do the change. We also had a problem with the overdrive shift.

are you sure it has a voltage regulator most of these trucks had computer controlled field for adjusting charging voltage

Mine already seems to have an external, which might be what the PO already did, it does have crimp butt splices on the connector that goes to the voltage regulator. Seems the only thing that the PCM is doing right now is sending 12V to the regulator and field winding to energize it during key on operation. Aside from that, the other field wire goes to the regulator and it's grounded with the screws that attach it to the fenderwell. My OD was having an issue too, so it's wired to a toggle switch to kick into OD when needed, already had to bypass that system so I'm guessing the PCM is pretty much FUBAR. The wait to start light is on and off at odd times. Off during start up, and then sometimes on while running. Any idea where I can find another PCM to remedy some of the things instead of continuing to bypass things? I know for now how to bypass the PCM system and make it work, but right now it's not even working with the external transistorized regulator, I'm guessing it may need a better ground wired to it.