Alt? Batt? Volt Regulator?

[Untamed]

I've driven my 88TA a few times now, and noticed a consistant drop in voltage on the battery everytime I start it up. It's now at the point where there isn't enough juice to start the car without jumping it.

Normally I wold attribute that to a bad alternator and just get a new one. So I took it to Autozone, they tested the alt, and said it was fine. Its the original, 19 yr old alt for the car. Normally, after a car is started, the alt provides the juice for everything to run, right? That batt is only needed for starting. On my car, it looks like the batt is constantly being used as I drive. There's no loss of power when the car isn't running - the batt has just as much juice when I try to start it, as when I shut it down the last time I drove it.

So the kid at Autozone says it might be the voltage regulator. I've never dealt with one so don't know what to look for / what it actually does. Could this voltage regulator prevent the alternator from giving the electrical system the juice it needs to run everything? He said the volt regulator is not located in the alternator, its a separate system.

Any help?

[V]

put a voltmeter on the battery while the car is running and see what the voltage is, and also test it at the back of the alt to see the voltage there. an old wire maybe not be allowign the battery to charge properly. and afaik, there is no seperate voltate regulator.

[Tru2Chevy]

Yea. Correct me if I'm wrong, but I think most alternators have been internally regulated for several decades now....

- Justin

[JSPERFORMANCE]

could be loose, broken, or dirty cables/connections at the alternator and or battery

[johnjzjz]

my guess its the brushes in side the alt -- when car heats up they -- the brushes do not nake a good contact and auto zone does not warm it up -- been right their many times with GM alt -- jz

[JSPERFORMANCE]

good point, seen that before as well

[Untamed]

Well I dunno guys. I put the alt back in, hooked everything up like it was before, and didn't do anything different other than jump the car when I started it. Sure enough, started right up. After disconnecting the jumper cables, I let it idle for 15 minutes on its own and it sat just fine at just a hair over 13 volts. Put the car in gear, flipped on the lights for some additional draw... and it ran and sounded just fine. Guage says its at 13 as I drove it around the storage place.

Strange. Just disconnecting everything and reconnecting, seems to have worked.

Thanks for the suggestions guys.

[JSPERFORMANCE]

bad connections. I win! What do I get?

[johnjzjz]

not so fast lets see in a day or so -- you know auto zone might have spun it backwards helping the brushes for 20 miles or so -- U NO __ hahahhah --jz

[1QWIKBIRD]

Well I dunno guys. I put the alt back in, hooked everything up like it was before, and didn't do anything different other than jump the car when I started it. Sure enough, started right up. After disconnecting the jumper cables, I let it idle for 15 minutes on its own and it sat just fine at just a hair over 13 volts. Put the car in gear, flipped on the lights for some additional draw... and it ran and sounded just fine. Guage says its at 13 as I drove it around the storage place.

Strange. Just disconnecting everything and reconnecting, seems to have worked.

Thanks for the suggestions guys.

If you are only seeing 13 volts at the battery or at the back of the alternator, you still have a charging issue, I think.....you should see 14.2-14.5 volts. Sounds ticky tacky, but 13 volts isn't enough to sustain the battery over time. Do you have another vehicle to check, anything. make sure your multimeter is working correctly.

Chris