I recently noticed that my battery light is always staying on. I tested the battery itself and the alt. and both are working fine.

The problem is, every now and again, maybe 5% of the time my car wont start with the battery light on.

Any ideas as what may be the problem?

Thanks

 

Check your fuses and alternator wiring

 

how are you checking your alternator? are you using a voltmeter at the power terminal and chassis ground? you should be getting 14.5 volts.

then read the battery voltage. should be the same.

then measure the resistance from the positive battery terminal to the alternator terminal. should be close to zero. (i think).

other thing to check is the battery terminals themselves. they get loose. especially when its cold. that would prevent starting up.

otherwise, id still question that "battery" light. its actually a "charge warning" light. really nothing to do with the battery. its all to do with the alternator and its saying the alternator is not doing its job. so the alternator probably still needs replacing.

 

Check your grounds also. Alot of people have problems w/the grounds. Check the one attached to the thermostat, that one would definately keep your car from starting. I had a problem once with the one from the rad support to the valve cover. It would heat up and the car would not start. I now run extra ground wires from my frame to my engine just to be sure.

 

I have the same problem with the battery!

 

Tyson - yes I was using a voltmeter, and got 14.02 with my lights and stereo on. Terminals are tight and clean.

Wicked - I'm going to check that later today

Honda - I'll check my grounds in a bit going to grab something to eat.

Thanks for your help guys. Anymore suggestions would be great incase these don't solve the problem

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MDAnhorn &raquo;</TD></TR><TR><TD CLASS="quote">Tyson - yes I was using a voltmeter, and got 14.02 with my lights and stereo on. Terminals are tight and clean.</TD></TR></TABLE>

14.02 isnt enough. it should be 14.5V. thats why its on. tells me that the voltage regulator isnt good anymore. alternator needs to be replaced.

 

Have the Alt tested before you replace it. I only get just under or around 14 w/all of the hondas I've had and my battery stays charged and the battery light isn't on.