Alright guys, this has probably been covered serveral times but I can't find it. I don't have a Service Manual and the truck charges for weeks at a time and then just stops. It will run for a week without the lights on before I have to charge it back up.

How do you check the internal voltage regulator on a 1992?

 

If nothing else is messing up, i would say that the crank sensor(out on top of the harmonic balancer ) is bad or wire to it is broken.

 

The voltage regulator is in the PCM.

Like Flash said, check the crank sensor and wiring. If that's in good shape, try swapping the relays on the fender. The charging relay is the front one, swap one of the others in and see if that clears it up.

 

I finally got around to working on the truck this weekend. I tried swapping the relays, no change. I knew the VR was in the PCM, just wanted to know if there was a easy way to check it. It ended up being the alternator, only putting out 10.5v. The new one puts out 14-16v. Now to get the inj. pump leaks fixed and I'll be ready for winter.