so i installed a PA 3g 130 amp alternator
when i initially started the car after it hovered around 14volts. Then took it for a drive and when i came to a stop the volts dropped to about 12 then jumped to 14.
What wire could be lose?
checked it with a voltmeter and it seems gauge is off by .9 to as high as 1.2volts... lowest it went with heat on full blast, radio turned up all the way and lights on was 11.9volts.. gauge showed lower though.. lol
Do you have any underdrive pulleys? If so that can slow down the alternator at idle. If you want to speed up the alternator get a smaller pulley. If you do not have underdrive pulleys I would first double check all connections, also make sure the 200A fuse is not blown on the 4ga power wire PA provides to see if it is blown. If everything checks out pull the alternator go to the closest autozone or advance they normally have test equipment to make sure the alternator is good. Let us know what you find.
Should be getting around 12.5V to 13.5V with all of the accessories on. I have 1,000 watts and with the AC on I have never pulled below 13V at idle with the 3G alternator swap and I got my alternator out of the junk yard from a 94 mustang donor car.
Where did you get the alternator? Have you checked all of your grounds? Did you have this problem before the upgrade? Std voltage should stay at 13volt min with all acc on like trevans said. Sounds like the new alternator has a bad voltage regulator. I would take it off and take it to advanced auto or someone to have it checked. If it shows good (make them test it 2x) check your grounds. best of luck man.