Alternator Numbers
Thread Starter
Advanced
Joined: Mar 2011
Posts: 93
Likes: 12
From: NY
Alternator Numbers
I just tester my altternator and it tested bad. Only 12.5 volts with eng. running. Removed alt. and found these numbers 1100827 22A 78 E24 12 V NEG. I am pretty sure this not the original. What is it? What should I replace it with. Not interested being number matching. Just want proper alt. 1972 454 MT, PS,PB with .AIR Thanks, Bob
Drifting
Joined: Aug 2019
Posts: 1,336
Likes: 225
If your numbers are correct, that's a 22 amp alternator. 71's with a/c should have a 61 amp alternator. I think if you just went to a store, it would be listed as with a/c, or without a/c. If you tell the person you have a/c, that should do it.
Racer
Joined: Apr 2009
Posts: 331
Likes: 44
From: Cincinnati Ohio
If you are running electric fans and halogen headlights you probably need to up the amperage. I have a 100 amp Powermaster on my 73 Corvette and 150 amp Powermasters on my 37 Chevrolet with a Big Block and my 55 Chevrolet. If your lights dim at idle, you don't have enough amps. If you have an have an electronic ignition it may drop enough to stop the engine. I had one that would drop to around 10 amps at idle, now it consistently stays above 12 at idle. All this electrical stuff we add increases the need for amperage for the alternator. The new car makers are agonizing over possibly changing to 42 volt systems in the future because of all the electrical demand not just for all electric vehicles.
