Went to go play in the mud yesterday and as I was driving home from my Dr Appointment after mudding my "Check Gauges" light came on and my battery gauge dropped all the way down and my radio started to freak out with all these cut outs in the music.

I went home, I thought it was the battery so I cleaned the posts and terminals went to go drive it and at about 35mph here we go again the Check gauges light comes on and my battery drops all the way down. I read up on this problem but I just want to make sure... Could this be due to the alternator not charging?

99 XJ I-6 4.0L

 

Any CEL codes? Mine was related to a low batt voltage when the rpm was above 1600rpm or something.

Basically turned out to be both the battery having a failed cell, and the alternator not charging properly. Swapped the battery out and it was fine for a while, but the check gauges light came back on intermittently. Changed the alternator an I am finally seeing +14.2v for the first time on my Jeep. Has not returned since I installed the new alt.

 

Nope haven't gotten any codes yet I might have to change it fast though because even when I turn the key to just the ON position the light goes away until I drive it then it comes on but now I think it's draining my battery because yesterday when I turned it to the ON position the battery gauge was around 12-13 now it's 10-11... Do you think it's the Alt?

 

The alternator is mounted so low that the water and mud you just went through packs into it and shorts it out. I would bet money that rebuilding/replacing your alt will fix your problem

 

You can have both your battery and alternator tested. Save alot of time.

 

That's what I'm gonna do when I get to work on Friday

 

That's what I was thinking too! Because there's a lot of mud on it that's all dried up and crap

 

My alt Did the same thing after i went through a lot of mud and i pulled out the alt and let it dry out all day long and put it back on and it's still going strong