Hello everyone. I am having an issue with my 2008 f250. Yesterday I was driving into my driveway and the truck just died on me. Shortly before dying the battery light lit up on the dash. I assume this problem is going to be an alternator. Seeing how these are the original batteries from when I first bought the truck I decided to go ahead and replace them. I put in the first battery and immediately heard a sizzling sound followed by a burning smell then smoke coming from somewhere right below the battery. I disconnected it and pulled it out. Out of curiosity I decided to put the other battery in on the other side of the truck. Immediately after connecting this one. I got the same thing. Sizzling sound, burning smell and smoke. But this time on the opposite side of the truck right against the firewall. Does anyone have any idea what this could be? I have never had anything like this happen.

 

Some type of short is what it sounds like. Are you sure that you put the correct wire on the terminal of the batteries?

 

Got it figured out. I assume there was a short in the alternator. As soon as I replaced the alternator and put the batteries back in no more smoke and everything worked fine. When I had the alternator tested it did absolutely nothing. It was beyond dead.

 

I would check the wiring to make sure you do not have some burned insulation, if you got smoke you probably have some burned wires, time to fix them before you have a major problem. The alternator may have been shorted and that could cause higher current draw than some of the wiring can handle. Better safe than sorry.

 

glad you found the short so quickly.

I agree with jetjockey to recheck as much wiring as you can see.

 

The first smoke I got was coming from the harness on the alternator and the second time was the positive cable. They both did have some burning and I did replace them both. Thanks guys.