i have a 72 cutlass supreme, and the car has been somewhat restored ( the reason i say this is bc there have been alot of cooks in the kitchen...if you know what i mean)

so here is my issue, new battery, new alt, new regulator (actually 3) i can charge my battery and it runs fine, when i get to my distination, i cut the car off and it wont start back up, so basically my alt isnt charging...so i thought...i had the alt tested, it is fine, the battery is new as well. i have changed the regulator, and it seems to work, but then after awhile it goes bad again, same issues. so i started testing power and i have good power to the alt. i started testing the regulator i un plugged the 4 wires, and i got power from two of the four ( i think two are for the guage, not sure) but here is where it gets interesting (keep in mind i am not good with Electrical issues) the red wire and i think a black wire show good power, then i plug it back into the regualtor the black wire(first one, closest to the hood) when i test it it is very very dim, like it isnt getting that much power, then i unplug and the test light gets very bright, so is it the regualtor? i am at a loss...please help, i hope this is clear. thanks


quick update....i have some time to kill, i did the "draw" test. i connected a test light from the positve battery cable (which is new, same with the negative cable) and to the positive terminal on the battery, is does show a very dim pulsating (blinking) draw, i pulled every fuse including the flasher and it didnt go off, i then started pulling off other plugs, coil, regulator, alt (both plugs) temp switch, oil light, it didnt turn off, please let me know if you have any ideas, i am going to pull my hair out. thanks

 

Starter solenoid?

 

where is it, and would it not allow my battery to charge?? how do i test? would it show the blinking draw? thanks for the input!

 

When you try to restart the car and it won't, is it that it won't turn over or is the battery totally dead and you have to recharge and it will start right up at that point? Even if the alt. wasn't charging the battery shouldn't be totally drained with one start up.

 

you are correct, it wont start until it is charged, once charged it will run, but when i stop...it is dead and it just clicks....does that help? i am running lights and radio.
and i run it for a little bit 15- 20mins

 

It should be on the starter, driver's side under the car.
Make sure you inspect all wires bolted to the starter for any cracks. Sometimes they get pinched by the inspection cover plate or the casing gets burned off by the exhaust.
Or your starter could just be bad and have a small short somewhere inside of it.

 

This is the key to the puzzle.

My money says someone has installed an internally regulated alternator on this car along with keeping the original external unit on the firewall.

Look at the plug on the alternator. If the car still has its firewall mounted regulator, plug should look like I I with a blue and a gray wire. An internally regulated alternator plug will look like - - and should have a red and a white wire.

Get the correct alternator for the application and I think your charging problem will go away.

If not, you have some wiring issues somewhere. You need to get a 1972 factory shop manual. It has color wiring diagrams that will show you where everything goes.

 

Okay so it will burn up the regulator, you replace it then all is good, then the new regulator will burn out in a short time right? As for the short I agree with J I would look for that on the starter and the associated wires they get alot of abuse down there.

 

so my plug has Blue and white/grey wire, and the plug looks like II not - - so that isn't good, so do i need to pull the starter or just the solenoid, also what would be causing the pulsating electrical draw? i am at a loss, here...i jsut don't know that much about electrical issues. thanks for everyone's patience and help.

 

so what should i do tomorrow? take off the starter and get it tested? same with the solenoid? i guess i am going to pick up a new regulator in hopes this one is bad/wrong...anything else? also did i test the draw correctly, but taking off the postive cable and testing between the pole on the battery and the cable? or do i have to do that on the negative? thanks again

 

The II plug is the one you want for externally regulated alternator. I don't think the starter is burning up your regulator, it could just be where that draw you found is comeing from, the solenoid is attached to the starter it will all come off at once if you decide to have it looked at. Is there any sign of the wire harness being cut between the alternator and the regulator? Did you try replacing the capcitor when you changed the regulator, if that is shorted out it could mess up the regulator? When you take the regulator off open it up and post what it looks like inside of it( what is burnt up this might help narrow it down).

 

i switched out the regulator. it looks like it might have fixed the issue, we will see....stay tuned thanks for everyones help...