Originally Posted by Demo1986
The pulley was new with the alt. When I disconnect the battery while the truck is running itstalls. Shouldn't it still run without the bat connected? I was thinking of this right now at work. I'm gonna chk to see if the alt is grounded.
Absolutely not. An engine cannot run without a battery, unless its like a lawnmower, dirtbike, or other things like that. Newer vehicles from like the 70's? on up are computer controlled and have to have power to read sensors, open injectors, etc. And the alternator grounds at the mount. It doesn't have a ground cable to it.