Voltage is within normal range at about 13.5 volts, yet battery light is lit and stays on with no voltage drain even on a several hour drive I went on recently. I've always had the voltage light come on when the voltage was out of range typically due to a bad alternator. This is in an 88GT with auxiliary gauges.

I'm probably going to replace the alternator anyway, but it makes me curious now.

What else does the battery light indicate other than voltage low or high?

Sounds like a short in the wire to the bat light. If it grounds out it will stay lit.

Nope it was something inside the alternator, as I just replaced it and the light is off, and all systems are normal again.

I am still curious as what else the light is indicating if it turns on without a voltage outside the range. Any ideas?

If not shorted... alt regulator had problems cause light to be on.

Had the same exact problem, put in a Brand New alt, light went out, 2 days later, It's BACK ON Again ! but Still charges at 13.5-14 Annoying !

A couple of years ago - I had my battery light on and then I realised that I had all the brackets powder coated the I way I got round this was to put an earth strap from the dog bone bolt to the alternator and hey presto the light went out.

Moral of the story - make sure it is properly grounded before tearing the alternator it could save you time.

jon

There is a small part inside the alternator called a diode trio. It has three diodes that take power from the stator and feed the voltage regulator. If one of the three diodes fail, the alternator will put out near full power, but the light will stay on. It is cheap and easy to install.

quote Originally posted by larry mimbs: There is a small part inside the alternator called a diode trio. It has three diodes that take power from the stator and feed the voltage regulator. If one of the three diodes fail, the alternator will put out near full power, but the light will stay on. It is cheap and easy to install.

No. 88 V6 have CS130 and CS130 doesn't have this item.