Hey guys.

'91 non intercooled d250 5spd. I came out one morning after it snowed all night and the truck wouldn't start. I jumped it considering the alternator would charge it but it didn't. Everything I used it would slowly drain and drain the battery. So I figured it was the alternator. Went and got it tested and it passed with flying colors. Battery is also good. Now I'm on the voltage regulator or crankshaft position sensor? Is there anyway I could test these parts? Any help is greatly appreciated! Connections on battery are tight and not corroded.

The day before I unplugged the trailer brake module under the dash since I don't need. Could that do with something ?

 

check the ground to the metal housing to the truck body, and also look at the bottom of your regulator. If its got a burned mark on the bottom, its been toasted. The Grounds are the usual problems, I usually get 2 or 3 , 8 ga. wires and run additional grounds, just to be safe.
If after cleaning grounds, and you try a new reg., you'll have to probably hook it up external style....

 

Okay thank you. It was a grounding issue. Thanks for the reply!