Bagitupbaby

i got a 91 5.0, in the nite wen u put on the headlights and heat or watever the voltage drops on the meter and everything dims but when u rev it goes back to normal, it taht problem the voltage regulator or alternator?

Twisted

My lights also dim at idle, and then flare with rpms. I thought that was normal if your idle is at about 750.

7upedition

go to autozone or napa and have them load test your charging system, the alternator may be fading its lifespan, or else your car is placing to great a load on the alternator with your accessories, the stock alternator is i believe 90 amps, a 3g conversion/upgrade will provide 135-140amps for recharge. load test first to see what the system is doing. do you experience any problems whent he accesories are all off, or only when you load it up?

Hawk

I agree with 7up that you might want to get your alternator tested. In terms of what you are describing though, it is normal for the voltage gauge to drop at idle when you have head lights on and other accessories. When you give it gas it comes back up some. You have to remember, the alternator is run off the same belt as your accessories and motor. So, when the car idles, the rpm's drop, and the alternator doesnt turn as fast. When you give it gas, the belt moves faster, the alternator spins faster, and your voltage comes back up.

Again though, get your alternator tested. Also, have your battery tested as well. Nothing will kill an alternator quicker than a dying battery. The alternator will work so hard trying to keep a dying battery charged that it will eventually fail itself.

Bagitupbaby

i had the alternater checked at R&S Strauss they said it had bad voltage drops, one of the mechanics took me to a place where they rebuilt alts and starters , went there yesturday and picked up one for 50 i put in this morning and the voltage meter was solid tonight ill see how the new one will hold up in the car

sgt50

Have you put on underdrive pulley's? That caused a problem for me.

Bagitupbaby

nope

Twisted

Hmm. Maybe I should have my alt checked also. I just assumed the dimming at idle was normal, as a lot of cars I've owned have done this, as well as all 8 motorcycles I've owned--if the idle was set low enough. To clarify, this isn't normal?