Help! Electrical Headache

[007]

Please Help. Today when I started my 81 vette, the battery light came on and the amps gauge was well below 13. When I parked it the night before, everything was normal. I tested my battery using my charger and it was close to 13. Did my alternator somehow pack it in over night?
I don't have a voltage meter to test its output, is there another way I can check it without unhooking the neg. terminal while the car is running?
Any suggestions would be greatly appreciated. Thanks.

007.

 

[22229stingray81]

I've had two alternators die just like that. Actually, one died right as I was driving. I'd suggest taking out the alternator and bringing it to Autozone, Pep Boys, etc. and have them test it.

You should note that the choke will not disengage with the alternator not working (choke needs constant 12 volts to disengage), so running it even for a little while would prove to be difficult, and if it reaches high idle, shutting it down would cause the engine to diesel. Ask me how I know :L

-Tatortot

 

[007]

Thanks Tatortot

I was in my shop changing out that alternator when you sent your reply.
Can't believe that it could die in its sleep!

 

[Vette D.R.S.]

It's the cool down cycle when it kills some and the heat up cycle for others.
I've also seen them fail in the cool down as yours overnight, when it does, it shorts the regulator, causes a drain on the battery, and will be dead or about 8 volts. in the morning

Dave

 

[08 ZHZ DUO]

Battery or Alternator

Acquire a multimeter ( radio shack has an inexpensive one), or maybe the maintenance dept. where you work will test it for you.
With the engine of /key off, read your battery voltage (should be 11.5 to 12.5 volts). Start your engine and the voltage should be 13.5 to 14.5 volts. This is all checked at the battery terminals. If you don't have that high of a reading, I suggest your alternator may be suspect. If you have the correct voltage reading, I would start looking for a loose connection (staring at the battery and working towards the ignition switch).

Good Luck.

Please Help. Today when I started my 81 vette, the battery light came on and the amps gauge was well below 13. When I parked it the night before, everything was normal. I tested my battery using my charger and it was close to 13. Did my alternator somehow pack it in over night?
I don't have a voltage meter to test its output, is there another way I can check it without unhooking the neg. terminal while the car is running?
Any suggestions would be greatly appreciated. Thanks.

007.

 

[007]

alternator

Hi Dave,
Thanks for the tip. I had no idea the cool down would kill it.

It's the cool down cycle when it kills some and the heat up cycle for others.
I've also seen them fail in the cool down as yours overnight, when it does, it shorts the regulator, causes a drain on the battery, and will be dead or about 8 volts. in the morning


Dave

 

[007]

Alternator

Thanks for the reply ZHZ. I do need a multimeter for sure. I pulled the alt. off the engine and had it bench tested. Diode trio was gone. I bought and installed a rebuild kit for $30. Works like new.

007.

Acquire a multimeter ( radio shack has an inexpensive one), or maybe the maintenance dept. where you work will test it for you.
With the engine of /key off, read your battery voltage (should be 11.5 to 12.5 volts). Start your engine and the voltage should be 13.5 to 14.5 volts. This is all checked at the battery terminals. If you don't have that high of a reading, I suggest your alternator may be suspect. If you have the correct voltage reading, I would start looking for a loose connection (staring at the battery and working towards the ignition switch).

Good Luck.

 

[Vette D.R.S.]

Ahhhhh the smell of VICTORY





Dave