My brother has an 08 6.7 with 60,000 mi.that i'm buying. It hadn't been started in 3 weeks and when I went to start it today the battery was dead(has one new battery and the other one is shot so it's unhooked) When I jumped it it started right up, so I took it for a drive and it died and It smelled like something burning. This Truck had sat atleast 2 years and a rat had built some nest's in the engine bay, which I cleaned/powerwashed out. After it died I went to jump it and the back of the alternator started smoking and when I touched it it was really really HOT, Did the alternator take a crap?

 

Could it be because I only have one battery hooked up?

 

It could be that. Were the cables for the other battery isolated and not touching anything?

 

Only the ground was unhooked, and isolated. How many volts should the tester read when running?

 

A properly working charging system should be sitting right at 13.8v-14.5 dependent on load. If you are going to run only one battery in it for now then you need to isolate the system down to one battery. Remove the + from the bad battery and the connection from the bad battery to the good battery.

 

So the Alternator took a crap, dont know why but it did. Got a used one (41,000mi. on it) for $70 with a year warrenty and all is good now.