91 dakota 3.9 auto. Truck overheated. Blew head gasket. I replaced head gasket and all other gaskets above them. After it was together, i started truck. Ran good. Put in drive and has no power. double checked everything. triple checked everything. smashed pedal to floor and raised rpms to 4000 a couple times. Something sounded better. Put in drive and had power. Engine light came on. Alternator dead. Replaced alternator. Back at no power. If alternator charges truck don't drive. Could use some help on this.

 

When you say "if alternator charges truck doesn't drive", what are you using to determine what mode the alternator is in? Also, which parts were removed during the head gasket repair job, and did you do both sides? Just trying to get a better picture of what might be going on.

 

If I connect the alternator, it won't drive. If I disconnect the alternator, it drives good. Pulled throttle body, distributor, AC compressor, alternator, intake, both exhaust, both heads. then reinstalled everything with new gaskets.

 

What does the volt gauge show when the alternator is hooked up? (engine running at idle.)

 

The gauge is not precise. It reads around 10 volts when disconnected. And around 15 when connected. Does not fluctuate when you rev the engine.

 

That's kinda weird...... Now, if the gauge is consistently low, then it's overcharging when it's hooked up. Can you verify that with a meter directly on the battery?

 

Will put a meter on it tomorrow, and post.

 

just battery is reading 11.9 volts. charging at idle highest reading i took was 14.5. Fluctuated between 13.4 and 14.5.

 

Ok, that is actually correct.

Did you move the distributor when you did the head gaskets?

 

I removed the distributor. Set to top dead center on number one, after repair. Replaced distributor. Timing would not be off? Runs good when alternator disconnected.