last nite i was at a red light and noticed since i put my voltage gage in that at idle with my music turned on 10 of 30 that my voltage droped to 12.7 which cant be normal i have 2 yellow top bats and a 200 amp alt. Question is how should i go about diagnosing the prob? thanks in advance guys
go to decent chain auto parts store and let them check your charging system on a computer for free. Only takes about 10 minutes to do the test. That is what I did.. L8r
dude u cant expect ur alt's idle output to push 2.5k without drop. Even if you have extra batteries.
I bet ur alt does 110amps @ idle best... and the amp is possibly drawing up to ~250amps.
@ a stoplight you are on the brakes and the car is in drive. Therefore ur alt is spinning at its slowest speed it could possibly be spinning. Not to mention add on the cars other electrical needs and you have even more amperage draw... And you know those brake lights? Yea even tho its smaller, its still drawing. I also noticed you said "last nite"... Well go ahead and add on your headlights drawing as well.
You just simply can't expect to be able to wang on ur system when ur at a stoplight. If its that important to you, put the car in park (illegal) and wait @ the light... You will releive your brake lights from drawing and your alt will spin faster.
it prolly the alt/ regulator dude take and put your car in drive turn headlights on and heat/air and take face plate off cd player so amps are not kicked on and see what your volt meter does then if it drops i would say alt or regulator is bad dude
