Another Dead short

[dstang97]

Now i have one in my drivers side alternator. This is not making sense. Advanced auto said it tested good. But when i have the wires hooked up and a test light from the negative to the battery it is still lighting up. What is weird is its not enough to pop a fuseable link.... So what gives? when i disconnect the wires the test light goes away. I am 99.9% sure it is not a cut in the wire.

That last short i had was a bad starter, but is fixed now.

 

[HikerMan]

One short I had that was keeping my truck from starting for awhile was a melted, grounded diode behind the air cleaner that made the short on and off, confusing the **** out of me. Not sure if this will help, but good luck

 

[dstang97]

Got it narrowed down to drivers side alt. but thanks

 

[dstang97]

I'm going to swap out another used alternator and see what happens. I do not trust the people down at advanced auto. I will report back later on in the day.

 

[doghead]

I've read many posts here, where people say the auto store tested their alt and said it was "good", when in fact it has had a bad diode or regulator, causing a slow draw/short.