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My alternator is draining my battery on my 1980 L82 c3
There’s a plug on the alternator if you use it a red battery light will turn on in the dash and start draining the battery, it takes about 1-3 days for it to die completely. If I leave it unplugged it doesn’t drain the battery, why’s it doing this? The guy at the garage who changed my alternator doesn’t know why it does this either.
I found a alternator that’s similar here.
https://www.corvetteforum.com/forums/c3-tech-performance/3526097-alternator-1972-corvette.html
its the plug in the middle with get 2 fork prongs, on my alternator it’s more on the side
That's the standard plug. Perhaps your wires are backwards? The two wires should be in a plastic plug assembly, and there is a right way and a wrong way to do it (documented in that link). This is the connector. The colors are wrong for a C3, but the connector is correct. C3 alternators often need to be "clocked" to work, or to appear stock. Can you post a photo? Just outboard of up is the correct location for the C3s. Here's a link with photos.
That said, your battery may also be draining because of a failed diode in the alternator. Just because a part is new doesn't mean it works correctly out of the box.
Bad diode is the first thing I thought when I seen the title to this thread. The diodes are extremely inexpensive and fairly easy to replace.
If your mechanic has never heard of this I truly wonder about his or her training.
This is a relatively common issue.
O.K. You need to find a gray haired OLD mechanic.
Someone like Me! But in your neighborhood .
Look for a mechanic that's well and truly over 60 years old and still doing this.
Anyone else is a waste of time and money as far as your Corvette is concerned.
Seriously,
"I did what my computer told me to do!"
Bloody parts changer technician.
You need a real mechanic, One that can think without a computer.
A techician changes parts. That's all.
A Mechanic can repair your parts.
And repair his mistakes if nessesary. LOL.
There’s a plug on the alternator if you use it a red battery light will turn on in the dash and start draining the battery, it takes about 1-3 days for it to die completely. If I leave it unplugged it doesn’t drain the battery, why’s it doing this? The guy at the garage who changed my alternator doesn’t know why it does this either.
Maybe its the angle of the photo but, I see only one connector tab on that ALT.
Maybe that is a One Wire ALT? Maybe that is an issue?
I hate the concept of the connector port facing straight up. It does nothing but collect engine bay dirt in that position.
Some people clock the housing, so the connector port is closer to the inner fender-well wiring harness.
A tool slipped and broke pigtail shown in your hand on mine last week. Found a duplicate one on Ebay. You would not believe the yrs & yrs of greasy grime down inside that connector port. I sprayed several Q-Tips with degreaser to make a good connection.
and the electricity is leaking out...sorry the internet told me that!
Maybe its the angle of the photo but, I see only one connector tab on that ALT.
Yeah, me too, and if the mechanic is looking at you tube then this could be and easy mistake....Look at your old alternator to see if it has two spades...
do you still have old alternator? if original get it back and rebuild it..with NOS parts..
i found there IS a difference in chinesium rebuilds and OEM for me with identical loads 50 RPM!!
around post 98, and videos on post 114. 115 identical loads. folks say alternators only draw x power i agree but i had a 50 RPM drop on same load.. i wonder what HP that equates to???? https://www.corvetteforum.com/forums...uestion-7.html
09-15-2022, 10:17 AM
My alternator is draining my battery on my 1980 L82 c3
