As soon as you get the new alternator in run a test on it. Get the engine started and then read voltage. Start turning things on and see when it drops below 13.6 v. When it drops shut that item off and start checking for the short in that circuit. If it's headlights you may have a short in the headlight switch or wiring. Whatever brings the voltage too far down is the culprit that's overworking the alternator and causing them to fail prematurely. Just have to keep trying things until you see which draws the excessive amps, and then troubleshoot that circuit and device.

 

Good idea Vall, knowing the headlights are what causes the most significant drop, I'm going to start there. However, it seems to be both the headlights and the blower motor that are causing this, I bet there's problems both places. Finding a short in the headlight wiring should be interesting. When I got the car last summer only one headlight worked and one parking light. Had to kinda jiggle the connectors to make a good contact to get the lights working. Do you think something like a bad contact with one of the connectors could cause this kind of draw? I should get a new headlight switch anyway, it's the original switch still.

 

Something causing a power drop as the car sits is not going to toast a good alternator. Inside the alternator are what's called diodes. Those allow charging power to flow only one way....out and to the battery. Since power is constantly live to the alternator, without diodes, the alternator would cook and the battery would go dead. Power can't feed back inside the alternator, unless you have a blown diode. Might be a good idea to take your present alternator in, have it tested to see exactly what is wrong with it (not just that it has low output). A good tester will tell if it's the voltage regulator, diode, stator, etc.

 

Pulling the battery cable is a good way to spike the alternator diodes, and kill the alternator. This trick used to work way back when cars used generators, but not a good idea with alternators.

 

I'll take it somewhere tomorrow and get it tested. I've got it all packaged up to go back but might as well see what's what I guess. I only pulled the battery cable off once on this alternator, but good to know nonetheless. Would sure be nice to leave everything connected the way it's supposed to be AND be able to start it the next day! LOL

 

It doesn't have to be a short to cause an excess load on the charging circuit. It can be a high resistance in a heavy load like headlights or blower. Something that draws 7-8 amps normally, can draw twice that if there's a poor connection in the wiring. The resistance makes the voltage go low and that makes the amperage go high.
There are numerous connectors in bboth systems, plus switches, and don't forget the bulkhead connector in the firewall! That one has caused issues on more than one old car. I've seen them so burnt up inside that there was no plastic between connections and turning one item on caused a short to another and turned it on too.

 

I'm going to run this alternator up and have it tested in a bit. Knowing the voltage drop is most severe when the lights are turned on, I'm going to start with those. With just parking lights on it still happens, just not as fast of course. When I turn the headlights on, the switch makes kind of a "humming" sound but everything works fine. I've just had the switch out when I was redoing the guage faces and I checked the wiring there and didn't see any cuts/breaks etc.

Not very sure what the bulkhead connector is or exactly where for that matter so I'll start at the other end and pray for some luck.

 

I "tried" to get the alternator tested today and couldn't even manage to have luck with that. 3 different stores and 3 different reasons why they couldn't test it for me today. That's the kind of luck I've had with this problem so I'm really not surprised. I ordered a new headlight switch and a couple new headlight connectors today. Who knows if they'll help or not but for $15, can't hurt. Hopefully the new headlight switch will stop the noise the current one makes when the lights are on. However I do have a question about the new headlight connectors:

The connectors on the Camaro currently each have 6 wires coming out of the back which I assume is for hi and low beams? The new plugs only have 3 wires each? Will I need to swap out the other 3 wires into these new plugs?

 

I'm not sure why the new connectors would have three wires, unless the two are to replace the one with 6. I'm also not sure I'd replace the connectors unless you pull the switch and see signs the connectors are burnt, which will mean they needed replacing.
The "bulkhed connector" is the main connector that sits in the firewall near the brake master and has most of your wiring going through it. The connector holds on with two screws if I remember right, and will have a non conductive grease insde to weather proof it.

 

I got the alternator tested today and it's got nothing wrong with it. The guy said it's putting out just shy of 14 volts. Said he ran every test he could on it and there's nothing wrong with it. With that said, and taking your previous suggestion of turning things on until it drops below 13.6 volts and starting there. All I have to do is get the Camaro started and it's below 13.6 volts before anything else gets turned on. I'm still going to check the wiring for the headlights and change out the switch when it gets here. It's time to get this BS figured out. All I know is that if the headlights are not turned on or the blower the voltage sticks right at 12.6 and doesn't fluctuate, but it also doesn't charge the battery.