Alternator going bad??
Thread Starter
Le Mans Master
Joined: Sep 2002
Posts: 6,569
Likes: 2,401
From: Redacted
Alternator going bad??
Ive noticed recently that with my headlights on, any time I add an additional electrical load, ie blinker, windows, etc, all the lights in the car dim. Is my alternator going bad?? Its a 2003 with about 30K on it. Thanks for the help!
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Check/clean your battery terminal connections as well as your grounds to the frame. Tip: be careful when loosening/re-tightening the nuts on the frame ground studs. If they are corroded or seem resistant to loosening, hit'em with some penetrant first. The studs that the nuts go on are spotwelded to the frame and it's best to not snap any off. They take a 10mm socket. I mention this due to your being fairly close to the Gulf Coast and the salt air.
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Make SURE that the starter solenoid B+ connection is clean and tight. A high resistance there can cause this issue to intensify. There has always been some LOAD FLICKERING in the C5 but if it gets excessive, there may be some underlying issues causing it.
What does your IPC volt meter and the DIC voltmeter read compared to what the voltage is directly on the POS and NEG post on the battery. They should be VERY close to the same reading.
The reason I want you to compare them is; the ignition switch can cause a significant voltage drop (due to burnt contacts) and all the modules and circuits that it supplies will see less voltage than it should have.
Check out this post and see if you can take some of the voltage reading that are detailed on the fuses that supply the "HOT in RUN and START" voltages to each module.
- http://forums.corvetteforum.com/c5-t...ch-repair.html
Let me know what you see when you take the readings or if you have any other questions.
Bill
What does your IPC volt meter and the DIC voltmeter read compared to what the voltage is directly on the POS and NEG post on the battery. They should be VERY close to the same reading.
The reason I want you to compare them is; the ignition switch can cause a significant voltage drop (due to burnt contacts) and all the modules and circuits that it supplies will see less voltage than it should have.
Check out this post and see if you can take some of the voltage reading that are detailed on the fuses that supply the "HOT in RUN and START" voltages to each module.
- http://forums.corvetteforum.com/c5-t...ch-repair.html
Let me know what you see when you take the readings or if you have any other questions.
Bill
Last edited by Bill Curlee; Jan 9, 2011 at 09:56 AM.
Melting Slicks
Joined: Sep 2006
Posts: 2,736
Likes: 7
From: Redding CA
I'm dealing with a very similar issue right now...BUT sometimes when I'm driving my headlights will actually dim for a brief second and I can watch the voltmeter drop to 12.5 volts or lower before they quickly brighten back up and the voltage meters goes back above 13.5..
I'm going to check all the starter solenoid connections.
Any luck with yours?
I'm going to check all the starter solenoid connections.
Any luck with yours?
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Until you investigate the HIGH CURRENT/CHARGING connections at the battery / starter & Alternator, I cant give you any more direction. Thats the starting point and the areas that most often cause this issues like your seeing.
Those areas have to be spotless and tight or there going to drop a LOT of current and you will continue to have issues.
The voltage difference between what is read directly on the battery terminals and what is seen on the DIC volt meter is another indication of trouble. They should be very close. The further they are apart, the worse your ignition switch contacts for that circuit are.
Like it was stated earlier, C5s experience some flickering when different loads turn on and off.
BC
Those areas have to be spotless and tight or there going to drop a LOT of current and you will continue to have issues.
The voltage difference between what is read directly on the battery terminals and what is seen on the DIC volt meter is another indication of trouble. They should be very close. The further they are apart, the worse your ignition switch contacts for that circuit are.
Like it was stated earlier, C5s experience some flickering when different loads turn on and off.
BC
Thread Starter
Le Mans Master
Joined: Sep 2002
Posts: 6,569
Likes: 2,401
From: Redacted
mine ended up being the grounding wires on each side of the engine bay. The terminal on both were slightly corroded with some sand/dirt build up in the plug. I cleaned them out, then filled the plugs with some dielectric grease and put them back together. Havent had any problems since.
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