I'm having an odd issue with my 2000 xj sport 4.0 4x4. When driving on the highway I would randomly get a check gauges light and the volt gauge would be at 19v. then it'd go away after a while, then come back, repeat till I'm off the highway. I just noticed today that my lights have a slight flicker to them. Batteries good, less than 3 years old. Alt seems like its doing its job, I have no issues with how the truck overall is running. I checked all the grounds and they seem good too.

I checked the battery with a DMM and it was good, about 12 without anything on, crank it over, settles at roughly 13.5. Rev it alittle and hold it, it jumps to 13.9, I'm sure if I held it more it would have gone up.

Now testing all this is without the gauge maxing out and the light being on but I can't really check that while driving...

I'm really hoping its not the voltage regulator because thats gonna cost. Any ideas? I've checked everything I'm about to take it to the dealer.

 

Ive heard the battery tem sensor can effect charging issue. Might wanna search deeper into it.

 

Battery temp sensor huh.... hmmm... Ive honestly never even heard of it.