RedFox16

After the original alternator finally gave out, I finally decided on a 130 amp upgrade. I got the new alternator, modified the bracket so it fit, and then rewired the power wire with 4gauge wire, replaced the battery with a 580 cca rating, and replaced the worn terminals. But every time I drive the car, at idle the volt meter on the instrument panel says 18 volts, and the battery light is on. When I give it gas, it goes even higher, and accessories act up (stereo shuts off, heater goes into overdrive, etc.) any help?? Please!??

edwin108

Check the battery voltage with a multimeter while the engine is running; it should not be higher than 15.5V around 1500 RPM. If your multimeter actually shows 18 volts, the voltage regulator in the alternator is probably bad.

RedFox16

So I replaced the alternator, because the regulator was bad. (They sold it with the test screw in it, and it fried the alternator). and now, I'm not getting any charge at all!! I am so lost! Everything is wired correctly. Just bad luck and a fault alternator?

edwin108

It could be, I would bring it to an auto parts store to have it tested. If you just bought it, it should have some sort of warranty.

Maxwelhse

Check to see if there is a do-dad on the voltage regulator is curiously sticking out of the rear of the alt. It's an assembly tag that holds a brush back while the alternator is assembled. If you see something like that, give it a gentle pull and it will come out of the alt and it should immediately start charging (see the little thing-a-ma-jig in the pic).

Otherwise... Nope, you've got another parts store dud alternator (rebuilt vs. re-manufactured vs "new" vs "NEW" oem parts). That is why I chose to rebuild mine myself. I bought a dud at the junkyard for $10 and bought all of the parts on ebay to upgrade it to 190A. The process wasn't too bad, just needed a BIG soldering iron. It also gave me the chance to have the case powder coated.