18 volts?? eecks!
Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 871
Likes: 2
From: Orlando Fl
18 volts?? eecks!
My 86 has started an odd problem...
Sometimes my vette will spike up to 17-18 volts. It drops back down shortly to the "normal" 13.5 ish.
(as a side note, my headlights wont pop "up" all the time. I have to play with the switch for them to work.) The lights come on, just not raise
Im working off the assumption that my voltage regulator (in my alt) is shot, and that the headlight issue may be a bad relay caused by a spike. No fuses are blown.
any thoughts?
Sometimes my vette will spike up to 17-18 volts. It drops back down shortly to the "normal" 13.5 ish.
(as a side note, my headlights wont pop "up" all the time. I have to play with the switch for them to work.) The lights come on, just not raise
Im working off the assumption that my voltage regulator (in my alt) is shot, and that the headlight issue may be a bad relay caused by a spike. No fuses are blown.
any thoughts?
Last edited by Gazpar; Jan 26, 2007 at 11:32 AM.
Team Owner
Joined: Mar 2001
Posts: 30,846
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
On my 95 there's two fusible links. If one blows, you don't have enough volts. If the other one blows, you have too much. Check them as well and make sure they're not on the way out. They're slow blow so they don't go out all at once.
Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 871
Likes: 2
From: Orlando Fl
Where are the links at?
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
There are no fuses that one blowing causes low voltage (it could cause zero volts) and another blowing causing high voltage out of the alternator!!!!!!!!! You have a defective voltage regulator in your alternator and I wouldn't run the engine until you replace the voltage regulator (inside the alternator) or get another alternator. 18 volts can damage the ECM, dash cluster, radio, and a bunch of other of your electronics in the car. GM allows up to 16.0 volts out of the alternator.
Drifting
Joined: Aug 2006
Posts: 1,624
Likes: 2
From: Canandaigua New York
There are no fuses that one blowing causes low voltage (it could cause zero volts) and another blowing causing high voltage out of the alternator!!!!!!!!! You have a defective voltage regulator in your alternator and I wouldn't run the engine until you replace the voltage regulator (inside the alternator) or get another alternator. 18 volts can damage the ECM, dash cluster, radio, and a bunch of other of your electronics in the car. GM allows up to 16.0 volts out of the alternator.
There are two diodes in the regulator. If one diode 'opens' then you will have a low voltage condition.
On the other hand if one diode 'shorts' you will have a high voltage condition.
It would be like replacing one of the diodes with a solid piece of wire.
Safety Car
Joined: May 2002
Posts: 4,010
Likes: 26
From: Somewhere nowhere
soon, you'll be replacing every light buld in the car, dash lights, interior lights, cluster lights, everything.
The ECM should have an internal voltage regulator, but there definately is an upper limit.
The ECM should have an internal voltage regulator, but there definately is an upper limit.
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Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 871
Likes: 2
From: Orlando Fl
Thanks for all the good info...
For the record, It hasnt been driven since the prob started.
Im looking to use this as an oppurtunity to upgrade the alternator.
Thanks again, and Ill keep everyone posted
For the record, It hasnt been driven since the prob started.
Im looking to use this as an oppurtunity to upgrade the alternator.
Thanks again, and Ill keep everyone posted