93 Regal Check gauges - sometimes

Hi All,

It was a good year for my 93 Regal (3.8 V6) after I've replaced the TPS. But now once again I'm having some lights coming on. This time it's the "Check gauges". It just comes on at random, stays on for a while, then goes off. And it's not happening daily either. All gauges are in the normal range and the scantool didn't show any issues and no codes.

What I did notice was that when idling the battery voltage would slowly drop from 14.3V to 13.8V. This measurement was taken without the light being on... However i don't have any problems starting the car so i assume the battery is OK.

Any ideas?
Thanks!

Took a look through the schematics in my Haynes Buick manual and apparently the Check gages light is directly connected to the generator, so I would assume it has an issue. I checked the belt and it's fine.
Any other reasons why that light might come on? How exactly does the generator know to turn on that light? I just wanna know if I should measure smth else first to get confirmation or just take the generator out and get a new one... As I said, no error codes are set, everything is fine except the light going on randomly.

I finally managed to get the light to turn on while the scanner was attached to the car. Apprarently the voltage jumped from 11.4V(before ignition) to 14.6 or so when the light came on. the light turned off the moment i started the back window defogger and the voltage dropped to 14.4V.
Any ideas?

Thanks!

Have you checked the condition of the battery positive and negative cables and battery terminals. Also, is the battery the right one if it has ever been replaced. Make sure it has the proper rating. The reading with ignition to off sounds about a volt low. Wth engine running the voltage appears to be normal indicating the alternator is putting out properly but it may be out of tolerance or not regulating properly.

I believe the ECM module controls whether the check gauges MIL light or charging system light will turn on or off and monitors the charging system. From what I can see it sounds like an internal problem such as a voltage regulator with the alternator. Hopefully you can find a shop that can test the alternator and battery, otherwise I would start by replacing the alternator. Good luck.

Thanks for the reply! The battery was never replaced but i did clean the connections this summer (although the negative was kinda stuck so i didnt clean that too well). I bought the car with 132Kmiles about 2 years ago and its at 148Kmiles now. There's no big electricity consumer on board, radio is nothing fancy either. i think the voltage was that low because i havent driven the car in a few days.

i'll wait till spring to change the battery with a new one of equal or higher rating (to make sure it has enough juice!)... and then move on to the alternator - a remanufactured one should do the job. of course i'm hoping the car wont die by spring!
I'll keep you posted!

Thanks for the feedback. It must not be easy getting parts for a Buick living in Eastern Europe. Plus it must be cold there until the Spring. Good luck and let us know how it turns out.