Voltage Problem

[Slowrolla97]

Ok this problem is starting to piss me off. Every time I hit the brakes my cars voltage drops to about 13.0 and the cars idle will drop to about 500 and some time it will cut off. I have no idea what could be causeing this. I thought it might have something to do with vacuum but there are no vacuum leaks or anything. Do you think there is a problem in the brake light circuit? If you have any input please chime in. I am stumped on this one.

Edit: This is in a black top sr20 s13 hatch.

[daryl337]

Your brake light circuit might have too much of a draw on it, or your alternator could be on its way out. you could get a load test on the alternator, but chances are it is in the brake light circuit.

[los_inc]

go test your alternator homie
napa, autozone , advanced auto they should have a tester
-los

[Slowrolla97]

Ok will do. I will come back with the results. I just dont see how it could be the alt. cause it only happens when I hit the brakes. But it cant hurt ya know.