Low voltage idiot light

I own a 1999 Dodge Caravan, the other night on my way home, the low voltage light came on and my temp (needle guage) went down to “C” and remained stuck there. My mechanic tested my alternator and said it was “overcharging” the battery and did not need replacing. The light is still on. I replaced the temp sensor, but it is still not registering??? Any advice???

Did you change your alternator? I’ll assume you did. If you temp gage does not move, it’s possible you burned that up with 18-20 volts your alternator put out. You said “over charging”, it could be putting out too high voltage, or it could not be tapering off the current when the battary gets close to full charge. Both of which indicate a bad voltage reg. inside the alternator.

it was “overcharging” the battery and did not need replacing.

Is that what you intended to write?

~This makes good sense!!! Thank you very much for your reply!~

“Low voltage light?” What’s that? Never heard of such a thing.

An alternator that’s “overcharging” should be replaced.

You need a new mechanic.

Yes, the mechanic said it was overcharging the battery!

I changed out my own sensor for the temp guage, and the temp is still on “C” and moved slightly and once stayed in the middle for maybe 10 mins on a trip. Then it fell back to “C” and has remained stuck there! The same mechanic told me there is another sensor under the engine, and it was missing! so yes, I am wondering now, how many temp sensors there are on a Dodge Caravan!!!

This sounds like a computer problem. The computer’s logic board includes a voltage regulator circuit and the gauge works off the computer as well, I believe.