Alternator problems and battery light on dash?

CASSCARR

MEMBER
2014 JEEP PATRIOT
2.0L
4 CYL
2WD
AUTOMATIC
164,000 MILES

So yesterday my battery light came on I checked the alternator with a multimeter, and it was bad. The next day I went and got a brand new alternator and put it on but let me back up first whenever I took the old one off the copper wires inside of it were melted and some of the outer casing metal was melted I had never seen anything like it neither had the parts store. So with that being said I took the old one off put the new one on and it ran and sounded amazing best it's ever ran and like an hour or two later whenever I went to go drive it again to get gas the battery light came on again I go back home I test the battery with the multimeter the battery is good I start the car test it again it's no longer reading 12.6 it's reading 11.9 and lower like the alternator isn't working I don't know what to do next?

Sunday, July 13th, 2025 AT 7:14 AM

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
52,298 POSTS

Most of the time when this happens the battery is bad, and it takes out the alternator. This is why many garages will replace both at the same time. When you say brand new do you mean OEM for the dealer? Because the wires were melted it shows the system was forced to overcharge which will be the battery, unless you have a massive stereo system with amps. If not, I would get a replacement battery and alternator, you can tell them it is defective. Make sure the battery cables are clean and secured well. Please let us know what happens.

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Sunday, July 13th, 2025 AT 1:42 PM