jtg0210

While driving 2.5 hours home from a trip, I noticed my battery gauge was all the way down at 9V. The music started to cut out every now and then, as well as the windows rolling up and down really slow. Jeep starts up with no trouble. Is this a problem with my battery or maybe the alternator. It was also almost 100 degrees out today -- if the heat effects this at all. Any help would be much appreciated. Thanks.

fb97xj1

Check the voltage with a meter to see if it reads low as well. Just because. And clean the engine grounds. Even if they look clean, remove and clean until shiny. The XJ is very fussy with grounds, and can act quite strange when they get dirty. Check the cables while youre at it. Id even check for any pending trouble codes.

Big David

The Jeep WILL run with the battery disconnected. Remove the negative terminal & IF it still runs see how many volts are going to both terminals.
It should be around 14 volts. If not it's the alternator. If it dies as soon as the negative terminal is removed it's the alternator.
If you remove the positive terminal & it grounds out, the Jeep will die.

jtg0210

Battery only reads about 10V now and, of course, now I can't even get it to even start. Cleaned the terminals earlier so I don't think that's the problem. I'm guessing the battery just needs a recharge?