hey this is a weird deal.. we have a 99 f-350 with the 7.3 . the truck will run and drive as long as the alternator is not hooked up... if you hook up the alt. it dies!!! has a new alt. wires are good!! its weird. any ideas?

 

WELCOME to FTE!!!

Sounds like a bad alternator out of the box. Did your source bench test it before you put it on the truck?

 

its good! on the second one

 

when you installed new alternator did you disconnect both batteries before installing? If the positve wire grounded while installing the alt. it could have fried it, and also check your fuses(don't ask me how I know this, all I ll say is I've got the t-shirt to prove it)

Take the alternator back to source and have it benched again, to make sure it is not over charging, and check all fuses.