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eletrical gurus, thoughts needed


NAXJA Member #1376
Myrtle Beach, SC
Alright, 87 comanche with a winch, stereo w/ a 500 watt amp, 4-5 year old optima red top batt. and a 140 amp alterator.

My battery volts meter in the dash never comes out of the red anymore. no matter how long I drive. Even when turning every thing of in the truck. I know I should put a volt meter on the battery to see if that is the problem first, but is there any other things to check.


could be a bad meter. not sure how long optimas usually last but thats pretty old for a battery. which alt do you have? have the battery tested.

...are you saying its reading high or low?

The battery is reading 12.75 at the terminals.

the in dash meter is reading 10? volts, while driving.
the alternator is an aftermarket unit from some place in texas, I don't remeber the name though.
12.75 running or not running?
12.75 not running, I didn't get running read.
Yeah those in-dash factory volt meters are 100% pupu. I hated mine until I accidentally broke it. I superglued the needle at 12 volts and I'm permanently satisfied with it.
Mine generally reads low and at first I was concerned. So I busted out the old fluke 87 and saw it was pumping out about 13.5 running. Now when I look at I just keep in mind it reads a little low and just make sure it doesn't drop lower than what it normally says.
where does the in dash volt meter get its reading from?

I remember when I upgraded my battery cables it was reading 14 volts on the dash.
that's the first thing I'd do if I had upwards of 13V with the engine off. Replace those cables if you haven't done so already. I changed all the high draw cables on my 00 XJ with 00 wire (was free and readily available) and haven't had any problems since.