Big problem

My car has a major problem.  The electrical system has gone haywire on me.  The voltmeter stays at 11 volts when the car is on and even when i rev it up.  I took it to the car parts store in town and he said the battery is fine.  My car also starts really easy.  And when i turn on my system  or step on the brake the voltage goes even lower.  Could i need  a new alt or a voltage regulator? Thanks

Sounds to me like an alternator problem. Why didn't the shop test the alternator while they were at it ??Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA

It wasnt a shop it was just a store that sold car parts and i dont think that he the equipement and he was the only one working.  Anyway, my cousin is coming to my house tomorow and hes a mechanic at a chevy dealer so i will have him look at it.

At any rate, I would say look at the alternator and double check about the battery too. If the resting voltage is betweem 10.4 - 11 volts, you need a new battery as well. If it's between 11.8 - 12.4 volts , resting, it's OK still.Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA

At rest the battery was reading around 11.5 to 12 volts so he thought that the battery was ok.  I hope i get this fixed fast because i  miss my bass!

I would say to definately check the alternator if the voltage is lower then 13.8V when the car is running.Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

Tonite i tested the battery when the car was running and it was around 11.5 to 12 volts.  When i started and reved the engine, the voltage stayed the same.  Am i correct to assume that this is an alternator problem, like its not charging?

Sounds like something with the alternator is going out. Also depending on how old the car is and where you are located you may also want to check/replace the power cables going from the battery to the alternator.Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

Does anyone know how many amps the stock gm alt on my 1991 grand prix puts out?  I might put a bigger alt on for my system so i dont have the headlights dim.