Signs of when the Alternator goes bad

[Magus2727]

Today when starting the Jeep after driving it around and also being in the middle of a camping event in Yellowstone. The check engine light came on and the voltage appears to be around 12.5 (don't have a multimeter on me, just gauging where the dash volt meter is sitting). Using a external battery charger the battery pulled a 10 amp charge to charge for more than an hour (had to turn off the generator due to camp restrictions).

Would this be a sign of the Alternator going bad?

 

[JohnX]

If you only had 12.5 volts with xj running, then yes, your alternator is not charging. This does not necessarily mean that the alternator is bad, could be a blown fuse, could be a bad connection between alt. and battery, loose belt, etc.

Before jumping to conclusions, check charging voltage with a meter.

 

[Magus2727]

Well not really able to. But should be able to have them ch3ck it at the part store. It's just a 65 mile drive to the part store. I have checked fuses and moved and check connections and nothing was blown and no moving of connections cause the voltage to go up.

Going to see how well I can replace the alternative in the parking lot of the part store...

 

[Magus2727]

So looked at some YouTube videos on the subject of replacing to make sure there were no gotcha type moments.

It appears I have a different alternator and bracket than the videos....



I have some weird different 4 post connector in addition to the power plug. And some other plate/adapter that looks to be in the way of a clean removal from under the motor...

Thoughts?

 

[Magus2727]

Well, unlike the videos you find there is part of the body from below and AC lines above that prevent a easy slip in / out type of a situation. Ended up having to take both brackets also basically off in order to have clearance for the alternator to go in. about 1.5 hour job while working with limited tools in a NAPA parking lot. Not bad....

Any one know for what years they used this kind of Alternator vs the ones with a simple plug vs 4 terminated posts for the controller.