Trouble code 41, alternator?

[sbxj]

My check engine light comes on and the code is 41 (aternator field switch.) Today I cranked up the Jeep and watched my volt gauge go from 14v to 9v in 2 sec., then suddenly jump back to 14. I can cycle the ingintion and get the check engine light to go out. For the time being I'm just waiting for it to happen again. My question is why is it coming up and how can I fix it? Do I have to wait till I get stranded? Thanks all! 92 (voltage regulator inside computer module)

 

[SimpleXJ]

Most would say this is not a good way to test the alternator, but here it goes:

While running, unhook the neg batter cable from the battery. If the jeep dies then your alternator isn't working.

The fact that yours drops to 9v intermittently probably means your alternator is about to die. Almost any auto shop can test your charging system for you if you're not the type to get dirty.


SimpleXJ

 

[fire325]

oh boy, mines doing the same thing! check engine light came on, ran the trouble code, and sure enough, it flashed a trouble code of 12 (battery disconnected) followed by trouble code 41 (alternator field switch).

seen a write up on the JU board, that you can repair your alternator with a diode from radio shack??? :dunno: is this true, or do i need a new alternator? if i need a new alternator, what would be a direct swap with a little more amps, besides another factory alternator, GM, Ford etc.....