I just put in a rebuilt alternator in my 88 bird. The problem is when I drive at night lights on, my battery will be dead the following morning when I go to start it. It is carbd, no electronics to worry about. In the day time no lights or anything battery stays charged. I don't have a voltmeter, and since I have any electronics to worry about, I just pull the positive battery cable off to test alt. With no lights on, the car will run all day with no battery. If I try the same thing while lights are on, car cuts out for literally a second then I guess alternator kicks on then will run no battery connected. So I'm thinking somehow the alternator is not putting off sufficient charge. I don't know where to go from here and am tired of a dead battery.

 

Go to local auto parts store and have them check your alternator and battery for free. Alternator not putting out or battery not holding charge.

 

I've had the battery tested 3 times, the first time they said it was bad, took it to Walmart, they tested it said it was good, went back to autozone and it tested good, so 2 times out of 3 it tested good. The wiring on my car was a nightmare so I have the exciter wire from alternator wired into my switched fan. Could that pose a problem?

 

How old is the battery? Sounds a bit flaky. It's that one time that's gonna leave you stranded. If you're sure the alternator is good and you don't have tools to test, it's probably the battery. Also, update your profile, i'm assuming you have a TBI 305.

 

The battery is less than a year old, so I just drove the car and I know the alternator is not putting out enough amps or something BC when I have the car on and lights on, then turn car off while lights still on, I know they should dim, which they don't. I have a 30 min commute to work and the lights were dimming more and more the whole time, battery basically Dead when I arrive at work. While the car was still running and lights on, I disconnect pos terminal of battery and car will die, I turn off lights and disconnect pos battery terminal and car will continue to run. I even tried disconnecting sense wire to make alt put out full voltage, but still no change. Is there anything I can do to make the alt put out more volts?

 

The alternator is rated at a number of amps (100-105) and volts (13.2-14.2) to charge the battery. It has a built in regulator. Don't think you can increase that without a different alternator or changing out the voltage regulator inside the alternator.

 

And sorry it's a 305 quadrajet with hei

 

Looks like you may need a higher rated amp alternator. Best to invest in a inexpensive voltmeter and see what it's really putting out.

 

It's a 1988 car.

For the last 28 years, that alternator, whatever size it is, has been JUST FINE.

This is your problem, right there. Un-fornicate your wiring. Put it back like it belongs. No excuses, no "I can't", NONE of that, JUST DO IT. Your alt will then work just fine. (unless of course, if the alt itself is dead, in which case, an otherwise identical except non-dead one will work just fine in its place as it did for the last 28 years)

 

This is your problem, right there. Un-fornicate your wiring. Put it back like it belongs. No excuses, no "I can't", NONE of that, JUST DO IT. Your alt will then work just fine. (unless of course, if the alt itself is dead, in which case, an otherwise identical except non-dead one will work just fine in its place as it did for the last 28 years)[/QUOTE]

If I could put it back to factory at this time I would. I'm working with what I got, and when your wiring harness is hacked to sht, you have to make do with what you have, not everyone has the money to do things " factory", so yea there no excuse, unless you don't have the money. So back on subject, does a switched excite wire work? It just seems like the alternator is working just not putting out enough volts for the lights

 

When that happens, you UNHACK IT.

Hacking on it MORE won't make it better.

Money isn't the issue here, it's MENTAL DISCIPLINE.

Get rid of whatever hack some PO did to that circuit and put it back like it belongs. It costs no more to go find where the wire used to be hooked up to and splice it back there, than it does to splice it to a WRONG spot.

 

Looks like your not understanding me, the harness is UNRELIABLE BC ITS SO HACKED EVERYWHERE ELSE THAT I WOULD RATHER KEEP IT SIMPLE AND not rewire into it. The only thing the factory harness does now is power my lights. So enough about this mental discipline and back on subject. This is not a show car, it is a daily driver and I don't have time to make things perfect back to factory specs, point is this thing used to get charge with old alt until it went out. So I finally got a volt meter on it and running at the battery I'm getting 12 volts, 11 volts with lights on. So I think I may have just gotten a defective alternator, now I need to find time to pull this thing off and have it bench tested.

 

If at all possible , yes Sofa's method of putting it back to factory would be best . If you check the for sale ads here you may be able to find an unhacked harness for small cash and that would likely solve a bunch of other issues at the same time . Only you know your money situation and how far you want to go in getting a daily driver running .

Anyway , What I really wanted to say was , the method of testing an alternator's output by disconnecting the battery and then turning on the lights , has likely roasted as many alternators as headlights & ICMs and ECMs and even radios , pretty much anything with a transistor in it , when the thing that normally buffers huge voltage spikes in the system (The battery !) has been disconnected under load .

Don't do that again ......

 

Once again I know factory is best, but that isnt within my possibilities right now, as I'm not having any other issues but this, so no need to get an all new harness just for the alternator. So I took alt off to have it bench tested and it failed 3 times, so new alt will be here Tuesday. I'm just going to run the exciter wire through a diode to switched 12v and be done (hopefully)

 

You can swap it to 140A using this bracket kit....