Hi everyone. I periodically get the battery dash idiot light. When I check the charging level with a multi-meter at the battery with all lights on I get a 14.4 volt reading. At the alternator the reading is 15.2 volts. All of which seems fine to me. Why is the light illuminating? The other day the battery indicator came on and I had my factory fogs on they shut off, the headlights were dim. I checked the charging voltage when I got home and it was 11 volts. Not good obviously. I didn't do anything that night since it was late. Then next morning I started it up and the battery indictor was still illuminated but when I checked the charging voltage both at the battery(14.4 volts) and the alternator(15.2 volts) it seems fine. I left it home and got a ride to work that day. In the evening, no battery indicator. What the heck??? Three days without a problem and now again the battery light has come on but the charging voltages are fine. Any help/ideas are greatly appreciated.
Maybe amight help! LOL

 

I hope this doesn't sound belittling, but have you checked your cable connection? They could be loose. hopefully it's something that simple.

 

Hi GP thanks for the reply. I wish it was just that stupid, but it isn't. I have check the battery connections and the alternator connections as well.

 

Your internal voltage regulator may be reacting to the alternator heating up after a period of time. Track it over a period of time.

 

I read that the ECM controls the voltage regulating. I'm not sure if this is true.

 

I don't mean to be a PIA, but does "check" mean remove, clean, reinstall ? Corrosion is sneaky, grounds are vital. Someone had mentioned in another post about connectors not being properly seated, in harness and Fusebox...Also individual battery cells, would show up on draw down (load).

 

Thanks FL. I did remove and check and wiped off the connections. I'm pretty thorough when I do my mods and maintenance. It's just a weird problem. I can't seem to find any pattern or reason. I do have a piggyback unit to the ECM for the supercharger. I'm going to disconnect that just to eliminate that from being the problem and I will have to eliminate the supercharger for now so I don't throw any codes without the piggyback unit thanks for all ideas to you and everyone else!