You guys have any suggestion on Alternators / Brands? New opposed to rebuilt? I'm thinking of just swapping out alternators considering her car is 300 miles away and it'll be a couple weeks before I can get there to even check it out. Car has 107,000 miles on it. Though it's driven very little while on campus, my biggest fear would her being stuck somewhere between here and there.

 

Plan on checking out the battery, too. Interstate has a 3 yr free replacement on that battery. Only reason I bought it..

 

I know there is a code in the PCM for high voltage. I would think if there was any real chance of high voltage the PCM would not let the car start until the code was cleared because of the damage that could happen.

Back in the 80's GM sent out a notice to customer stating the number one reason for EMU failure was jumping older non-computer controled cars. Even one with nothing wrong with it would "full field" when it started and the voltage would shoot thru the jumper cables and fry the computer.

Also with a new battery if you are see a voltage spike in the morning it could be a sign of a small overnight drain. Something like a glove box lite or under hood lite not turning off. I have had a few customers replace batteries because of a small draw like that. They did not realize they had a issue intil the car sat for days then did not start.

 

You know, you might have hit the nail on the head... Being at college, her car may sit for days, if not a week, without being started. May have the very slightest drain somewhere. Any aftermarket or remans alternators out there worth a crap? Considering, because of the mileage, replacing it just for the piece of mind.

 

You could always have the alternator bench tested to verify whether it's in good working order. As far as reman'd goes, all depends on who you are buying from. Most remans are sent to have the internals replaced and the casing is usually the only thing that's original to it, so they're not a total waste of money.

 

If there is one around, take it to an Autozone. As long as the battery passes its test we can continue to a starting and charging test. The tester we use is an Autometer that puts the electrical system to a full load and will even show the voltage ripple as well as the actual voltage being put out by the alternator.
Most people don't realize we can test the alternator on the vehicle, as long as the battery is good.
Even if the battery fails(could come up charge and retest) ask the person to put the tester on the voltmeter setting, it wont put the system under load but will tell you the voltage and ripple of the alt.

 

I miss the days of VAT-28(1st choice) and VAT-40(2nd choice).

Having good connections at both ends of the battery cables and at the alt BATT stud will ensure a fully charged battery. Yes there will be a draw on the battery due to the radio, and ECM.

Another suggestion is get her a jump box from Harbor Freight and show her how to charge it and how to hook it up to the car. Reserve power in the trunk, or dorm room charging, only if used.

Just the other day, fellow worker said he had the GEN light 'on' on his Cavalier. Took voltmeter out and and charging 18 volts.
Suggested he replace the volt regulator and he said its easier to change the alt. Back to normal now.

 

Finally went to visit my daughter and checked the battery voltage (ok) and the Allernator voltage was 14.8. Looking like the guage is kind of iffy although it appeared to be working fine for me?

 

These gauges are notoriously inaccurate, as long as your volt meter showed good numbers I wouldn't worry about it.