on my 02 4runner i dont generally do very much mud, and for one main reason, my alternator has developed into the habit of frying when i do. today i was just out and went through a moderate puddle...enough to get the roof but it was around a corner maybe 15-25mph and 1 or 2 ft deep...i'm running stock aside from a deck, 2 12" subs, and some little led lights on the inside. so what could be the problem because i have gotten used to the battery light being on when its gone and needing a new alternator, so whats up? or could it just be the damn factory Toyota alternators i keep getting conned into buying? any help would be great.

 

Those damned factory alternators (and starters) are the best built components you can buy, hands down. thats not the problem.

Problem is probably both your sub amp, and mudding. Both take a toll on the alternator.

Although I have been mudding plenty of times and NEVER had an alternator problem.