I drove my xj into a mud hole and got stuck i had to wait for two hours for my buddy to come pull me out because my come along broke. the alternator was underwater and now that i got her out and all clined up the battery keeps running down after i charge it. if anyone knos what ight have caused this i would appriciate it.

 

I think you fried your alternator. Take it off go to kragen and have it tested. If it passes then at least you know its not that. Alternators can tolerate getting wet, but they aren't meant to be submerged and sitting in water the way you described.

 

[QUOTE=xjcrazy;1130124 Alternators can tolerate getting wet,[/QUOTE]


I don't think so, not while they are rotating and generating electricity. They will short out to ground and that equals a total failure.

If sitting on a bench and you spill your coffee into it, it can be dried out w/ compressed air and it will be fine thereafter.

 

[quote=xjcrazy;1130124 Alternators can tolerate getting wet,[/QUOTE]

I'm not so sure about that. The alternator on an XJ is pretty pretty low down on the front of the engine and I know I've gone thru a whole mess or deep standing water at a fair rate of speed and that thing had to get a good soaking in the process. But maybe it's a crap shoot and it's one of those things that either might or might not cause a problem.

 

While the alternator is not designed to be submerged we have done water crossings that did not affect the charging system. With that said... It depends upon how you go thru the water....
If you go thru slow and steady you probably will be fine, but if you BLAST thru causing water to be forced throughout the engine compartment then you will probably have problems with the charging system.
One of our member recently BLASTED thru the river and the check engine light came on.... We checked the alternator voltage and found it not to be charging.
On the trail we disconnected the battery, rinsed the alternator and then blew it out thoroughly..... The check engine light was gone and the alternator was again charging properly.
This is not something you would want to do to your alternator continually... It may short out totally as others have posted.