electrical...bat, alt?

so i was out wheelin yesterday in the snow/mud...lots of mud and the jeep starts to loose power and idle roughly. I stop and get out and open the hood to see whats up and it loaps and dies. measure the battery voltage and it reads 6.5V (optima red top). The jeep wont crank, so i get a jump from a friend and it runs just fine...for about 1/4 mile then it slowly dies again. this time we left the cables attached while his Kia idled for about 20 min. the jeep then started fine and drove fine for about 20 min till we got back to his house. measured the voltage there and it was at 12V and could start and run fine by itself. so i decided to drive home, another 45min and everything was fine except the voltage in the gauge cluster was only 9-10V and would go down if I had the headlights on...radio...GPS..etc. Here's the kicker...the voltage was below normal the entire drive home, but when i went through a huge puddle to wash off some mud, the voltage suddenly jumped to normal and all seems well now.

any ideas what was causing the problem? BTW, there was no mud in the alternator when the jeep died. All battery connections are clean.

I have to go an finish cleaning the jeep and get the smog tested, so ill see if it does anything funky on the way.

Thanks

well there are only a few things that will cause that alt bat or bad conection. i am assuming your bat is somewhat new. so that narrows it down to a bad alt or bad connection it is unusual for an alt to be shot and then get splashed and suddly come back full force. so i think i is a bad connection check the con between the alt and the bat there is a con on the alt and i beleive on the bat it is part of the lead terminal. next check where the pos goes into the engine compartment fuse box. if those are good start checking your grounds.

Take it to autozone, they'll test the alternator and battery for free.

Mud in New Mexico.......YAH RIGHT!?!?! jus playin.

Well, i didnt see a year and model on your post, but i would assume a connection or ground problem somewhere, Cherokee's are famous for these issues.

Cory

Thanks for the help!

the jeep passed smog and it seems to be just fine now. weird. I measured 14.65V at teh battery while running, so i guess the alt is fine. I cleaned all connections even though they looked fine. yea, the optima is 6mo old and i've redone all the cables with large gauge and ran grounds from bat to chassis and from bat to engine to chassis. i think it was one of the connectors.

I took a look at the cable that goes from the alt to the little metal box under the splash guard. its an '88. this cable is tiny and is all corroded, so im thinking ill replace it.

all is well now, so i guess the trouble is over. Thanks again.