Voltage Problem

[James 90GW]

Hello all!
I am a new owner of a 1990 GW. Just got it today after looking for one for a month or so. I am getting broke in right. To start with, I leave the used car lot. The gas gauge indicates slightly below 1/4 tank. I see the gas station and turn on the turn signal. Guess what? The thing cuts off as I'm turning in. No warning just cuts off. The entrance is on a grade and the new baby stops 75 feet short of the pump. Still on the grade so I can't push it. Have to buy a gas can, fill it up, put gas in the GW and drive 75' to the pump. Not a good start!!!!
Now to my problem. I had to turn on the lights on the way home and noticed they were getting bright then went dim. I watched the meter the rest of the way home. When the meter was around or slight ly higher than 13 the lights looked fine. The meter would then jump up to between 15 and 18 and the lights were really bright. I have a Hayne's book that says the regulator is either in the alternator or external from the alternator. If someone could give me a clue on where to look to find out I would appreciate it. I can already guess, but would like someone to tell me.
Thanks in Advance,
New Owner

[Joe Guilbeau]

Replace your alternator...

http://mysite.verizon.net/res00d4r/alt/Alternator_Theory.html

Read all about it...or just go down to the parts store and get yours tested, then replace it.

[Chevelleguy]

Do not, under any circumstance,buy an AutoZone alternator. They are total junk. And the CS130 upgrade, like Joe has and I have on my Chevelle, is worth its weight in gold.

[Bob N]

And as to the gas gauge, FSJs are known for inaccuracy....best to fill it up when it hits a quarter tank. And Welcome to the Addiction!

[andy d]

its internal on the later model delcos. the standard advice is to replace the alt. btw, the regulator is a 6$ part. the only drawback is that the alt has to be split to replace it. 1st time took me an hour or so to figure it out. i would advise taking it to an auto electric shop and seeing what they would charge to replace the regulator. overcharging is bad because it boils the battery. this can lead to an exploding battery. what ever you do , do it soon.

[James 90GW]

Thanks for your help. I replaced the alternator and it now works fine. I then figured out how the previous owner was raising and lowering the tailgate windows. Already coming up with thing I would like to replace starting with new exhaust. The current one looks pretty rusted but can probably wait till spring.

By the way, the Carolina Panthers are noe 5-0!!!!! Thanks to the Zebras for that one.