[92jeepyj]

I just got back from holidays and my jeep has not ran in 3 weeks. It fired right up and I drove it about 30 miles shut it off, then went to start it up and the battery was dead. I cleaned up the corrosion on the battery terminals, jump started it and drove it for a half hour and the shut it off, again the battery was dead. I am thinking that the alternator has bit the biscuit. I noticed a black wire on the back of the alternator is not attached to anything, not sure if it is supposed to be. When running the battery gauge is reading over half way towards the positive side.

Any help would be appreciated.

[Michael_94YJ]

I can't remember which wire the black wire is but it sounds like an alternator to me assuming you have good connections and good grounds everywhere else.

Were you running with lights and other accesories on?

[atomicmoose]

If the alternator was bad and the battery was dead, it wouldn't run at all.

I would get a new battery or get yours tested.

[Jeepaholik]

In the fuse block under the hood there are ,i believe, two 50 amp fuses that if either are blown(common) will not allow the alternator to charge the battery. looking at the block, starting with the 30a fuse closest to you they should be the 2nd and 6th fuses. take them out to check

[Jeep Man 10]

If the alternator was bad, you wouldn't be able to drive 5 minutes without it dying on you. I think your battery is toast dude.

[Michael_94YJ]

Simple solution, get both tested if all fuses and relays are good.

[pat8942]

Black wire should be grounded to the engine.

Originally Posted by 92jeepyj

I just got back from holidays and my jeep has not ran in 3 weeks. It fired right up and I drove it about 30 miles shut it off, then went to start it up and the battery was dead. I cleaned up the corrosion on the battery terminals, jump started it and drove it for a half hour and the shut it off, again the battery was dead. I am thinking that the alternator has bit the biscuit. I noticed a black wire on the back of the alternator is not attached to anything, not sure if it is supposed to be. When running the battery gauge is reading over half way towards the positive side.

Any help would be appreciated.

[92jeepyj]

Ok here are photos of the back of the alternator. Bad quality from my cell cam, but workable. I am wondering where that black wire should go? It has marks on the round end that indicate it was attached somewhere, but I don't feel anything close to it and that wire is really short.





I am charging the battery, but my one charger reads 100%

[sentinal02]

Originally Posted by Jeep Man 10

If the alternator was bad, you wouldn't be able to drive 5 minutes without it dying on you. I think your battery is toast dude.

x2. alt has to be putting out to be over 1/2 gage. if you're over 14V then the batt is probably shot and the computer is trying to compensate for the low voltage by ramping up the alts output.