Charging System on Overload
Thread Starter
Drifting
Joined: Mar 2006
Posts: 1,369
Likes: 79
From: West Coast
Charging System on Overload
This appears to be a standard issue of a failed Voltage Regulator, but before I start tearing apart the alternator, has anyone experienced a 1981 that the battery appears fine ( 12.5 after sitting for 2-3 weekends) and the voltage guage reading at a steady 16 volts at all times ( too high) and the red idiot light staying on even during long drives. The Light grows brigther the faster you drive and if you hit the power windows ( or any accesory) it lights up even brighter. I feared I may hve burned up a cell in the battery with the kicker subs but it checks out fine? Any insight woiuld be most helpful.
Thanks as always and cheers!
Thanks as always and cheers!
Le Mans Master
Joined: Aug 2000
Posts: 9,341
Likes: 0
From: Las Vegas Nevada
Mine does exactly the same thing with the exception of my volt meter reading right where it should where your's reads high. I repalced the battery because it had been sitting for about 3 years and there was no change. I'm guessing its probably a bad ground somewhere on the car so I'll be repalcing all my grounds next to see if that fixes it...
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
This appears to be a standard issue of a failed Voltage Regulator, but before I start tearing apart the alternator, has anyone experienced a 1981 that the battery appears fine ( 12.5 after sitting for 2-3 weekends) and the voltage guage reading at a steady 16 volts at all times ( too high) and the red idiot light staying on even during long drives. The Light grows brigther the faster you drive and if you hit the power windows ( or any accesory) it lights up even brighter. I feared I may hve burned up a cell in the battery with the kicker subs but it checks out fine? Any insight woiuld be most helpful.
Thanks as always and cheers!
Thanks as always and cheers!
And this is what you should be seeing with the car on fast idle or at least this is what mine shows.
Check out the other thread with my pics of regulator replacement pics.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
OK, you guys need check the voltages at your alt, with key off....
many times the wires to vettes in particular are confused with the replacement connectors for the SI series alternators, having two wires, flat in line white housing....the replacements are typically pigtailed out with odd color wires in sharks,....but the connectors are red and white wires....off the typical parts shelf...
the most clockwise connection is allways hot...viewed from alt backside....the other is hot ONLY when engine is running....and alt is charging....IF you turn on the key without starting engine, the LEAST clockwise term is grounding the lo side of a bulb or resisitor wire, so if you don't have a alt/bat/chg lite, you got a resistor wire....
if these are not hooked up correctly you can blast the regulator, in totally unknown modes...and then it's anyone's guess WTF happens....
many times the wires to vettes in particular are confused with the replacement connectors for the SI series alternators, having two wires, flat in line white housing....the replacements are typically pigtailed out with odd color wires in sharks,....but the connectors are red and white wires....off the typical parts shelf...
the most clockwise connection is allways hot...viewed from alt backside....the other is hot ONLY when engine is running....and alt is charging....IF you turn on the key without starting engine, the LEAST clockwise term is grounding the lo side of a bulb or resisitor wire, so if you don't have a alt/bat/chg lite, you got a resistor wire....
if these are not hooked up correctly you can blast the regulator, in totally unknown modes...and then it's anyone's guess WTF happens....
Thread Starter
Drifting
Joined: Mar 2006
Posts: 1,369
Likes: 79
From: West Coast
This sounds to me like the voltage regulator has failed. This is what you should be seeing with the car turned off.
And this is what you should be seeing with the car on fast idle or at least this is what mine shows.
Check out the other thread with my pics of regulator replacement pics.
And this is what you should be seeing with the car on fast idle or at least this is what mine shows.
Check out the other thread with my pics of regulator replacement pics.
Thread Starter
Drifting
Joined: Mar 2006
Posts: 1,369
Likes: 79
From: West Coast
Thanks for your help, unfortuntely I chickened out on the Alternator rebuild kit and and just went with a nice new Chrome 85amp upgrade unit. Looks great and no worries of me frying thousands of dollars of harnessess with a Bubba goofed up unit. Thanks for the input!
Drifting
Joined: Jul 2005
Posts: 1,891
Likes: 2
From: Baltimore MD
You need to read my post on my problems with my 81. you have 3 connections on the Alternator.
1. Where the pigtail plugs into the alternator at terminal 1 and terminal 2. (that's 2 connections in one plug).
2. The BAT connection.
There is a ground wire that is attached to the upper brace support as well. Not sure if I'd consider that an alternator connection or it's grouding something else.
Currently I've traced the Terminal 2 and the BAT red wires back to the solenoid on the starter for continuity. Bubba had done some strange wiring on this car in the past and I am in the process of correcting. Currently I have a new starter/solenoid to install. I hope this cures my problems, one being the horn blowing all the time the battery is connected - I obviously have a short to ground closing the horn relay somewhere.
1. Where the pigtail plugs into the alternator at terminal 1 and terminal 2. (that's 2 connections in one plug).
2. The BAT connection.
There is a ground wire that is attached to the upper brace support as well. Not sure if I'd consider that an alternator connection or it's grouding something else.
Currently I've traced the Terminal 2 and the BAT red wires back to the solenoid on the starter for continuity. Bubba had done some strange wiring on this car in the past and I am in the process of correcting. Currently I have a new starter/solenoid to install. I hope this cures my problems, one being the horn blowing all the time the battery is connected - I obviously have a short to ground closing the horn relay somewhere.
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