I have a 1992 bonne SE and I just replaced my alternator because it went completely dead. I notice when I am sitting at a stop light or sign my gauge goes down to about 9 volts. But when I take off it goes back up to about 13.8. It is really noticeable when I have the air conditioner on. When I turn it off it seems to be fine. Any thoughts. Another thing is that my Factory fog lights go off after about five minutes of operation and then stay off untill I get home. (About twenty Minutes). Any thoughts on that.


I took the car down to my local AUTO ZONE and Kragens for a test of the charging system and they say may Battery is good and the charging system is normal. What now.

Get a multimeter and check the voltage that way. It should be up close to 14 volts when the car is running. Even if it is above 12 you will probably be fine. Sounds more like a bad gauge than problems with Alternator or Battery.

The lights dim as well. Noticeable.

If thats the case you battery could be on its last leg. If you alternator was going bad for a while it would have stressed you battery. What kind of test did the stores do on the system. To trully check the battery you will need to have a Cranking or Cold Cranking Amp test done on it.

It was a hand held unit. They typed it the CCA on the battery into there little handheld device and that is what it said. That is why I took it to two different places and they both had the same hand held device

multi-meter?
you coulda done it at home... only 9buxx for a multi-meter, or you could get someone to rebuild a good anologe one for like 200... I got my sampson 260 series III sittin right here... never use it.. but if I need it.. it always works.

When they did the test did they go through a series of things like rev the engine for 7sec. --- let it idle --- turn on all accessory and lights --- rev engine again --- let idle and so on.

It does sound like the battery, but could also be the battery cables. Check both ends to be sure they are tight and not corroded. I had a similar problem on an old Ford Ranger, and a new set of cables cleaned her right up.

Got lucky, too. At the time I worked at a place where we made battery cables, so I custom made myself a set...

Even corrosion on the battery cables might cause interruptions in the electrical systems. If I were you I'd check the life on the battery, and since it will be out, might as well inspect the battery cable and clean the terminals.

:? sorry MOS...should read your post...duh...repitition anyone :P