Big problem
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Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=15249
Printed Date: May 14, 2025 at 10:29 AM
Topic: Big problem
Posted By: testes
Subject: Big problem
Date Posted: June 21, 2003 at 12:59 PM
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
Replies:
Posted By: Velocity Motors
Date Posted: June 21, 2003 at 3:54 PM
Sounds to me like an alternator problem. Why didn't the shop test the alternator while they were at it ??
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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: testes
Date Posted: June 21, 2003 at 4:03 PM
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.
Posted By: Velocity Motors
Date Posted: June 21, 2003 at 4:07 PM
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.
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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: testes
Date Posted: June 21, 2003 at 5:49 PM
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!
Posted By: auex
Date Posted: June 21, 2003 at 6:41 PM
I would say to definately check the alternator if the voltage is lower then 13.8V when the car is running.
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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.
Posted By: testes
Date Posted: June 21, 2003 at 7:45 PM
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?
Posted By: auex
Date Posted: June 21, 2003 at 9:12 PM
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.
Posted By: Velocity Motors
Date Posted: June 22, 2003 at 8:44 AM
I agree with auex. The voltage is suppose to be closer to 14 volts when running. You may need to get a new alternator or get the one you have now re-wound. ------------- Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: testes
Date Posted: June 22, 2003 at 9:02 AM
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.
Posted By: copcarguy
Date Posted: June 22, 2003 at 1:58 PM
Don't forget to check and clean your ground connections. Many, many problems relate back to poor grounding either at the connections or undersized wire for your additional equipment in the car. Just a thought. How about a capacitor instead of dropping the coin on a bigger alternator?
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R Jackson
Owner/Installer
TRM Emergency Vehicles
Information is advice only and should be confirmed with OEM or quality test equipment.
Boyertown, Pennsylvania
Posted By: testes
Date Posted: June 22, 2003 at 5:14 PM
Caps are not a fix to a lot of current draw. If the alternator cant push the power to the cap, theres no way that a cap can make up for lost power. Besides the price for an alternator and a cap is about the same. So i will probably fix the problem at the source. Does anyone know the amperage of the stock alt?
Posted By: copcarguy
Date Posted: June 22, 2003 at 9:04 PM
Sorry thought lights were dimming on the bass low notes from your previous reply that you miss your bass. Looks like you have all the answers!
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R Jackson
Owner/Installer
TRM Emergency Vehicles
Information is advice only and should be confirmed with OEM or quality test equipment.
Boyertown, Pennsylvania
Posted By: testes
Date Posted: June 22, 2003 at 9:40 PM
Oh, ok. I got the old alternator off tonite and i got to go to Car Quest tomorrow and get a new alt. I was suprised how easy it was to get it off. Three bolts, one wire, and the plug for the voltmeter in the dash.
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