RICHRAD

Whats happening is that when I start up and give the engine some throttle , my lights (all) brighten and my voltmeter shoots over to 18 volts. It falls back to about 13 - 14 when I let off. Is this my alternator or something else? Awhile back I clipped a wire in my choke relay so that my choke would only get power with my engine running . I had to do this because a particular relay wire was grounded out . However I did not notice anything with my voltmter at the time. Any help appreciated!

87tpi420

that sounds pretty normal to me. of course the lights will get brighter when you rev if up. and the volt meter will go up but when you drive the car, step on the gas and watch the voltmeter (AND THE ROAD) and it sould go up and then go back down. even while you are still revving it. the voltage regulator in your alternator will cut back so you dont overcharge (or it should atleast)
i am pretty sure you can check the charge wire from the alternator with a handheld voltmeter tester so see exactly what your voltage is. and watch it and rev it up for a minute and see if it drops either way....i dont think there is any problem. i have a heavy commercial truck that does that all the time.

bman

if its going to 18 volts its way to many and can damage the battery. If so it sounds like the voltage regulator in the alternator is going out.

RICHRAD

Thanks guys, Yeah it'll go past 18 into the red zone if I push it. I also checked the battery while running with a voltmeter. It reads 13-17.8 there depending on how much throttle I give it. I know these alternators can be checked for charging, but can they also be checked for regulating the charge. Can the average parts store tell me if it's messed up. If its bad, what should I go with. New, remanuf, or a rebuild kit ?