Battery light

[MPatty]

Two days ago I replaced the AC evaporator, condensor, and accumulator. I also replaced the glow plugs and fuel return lines. Yesterday I drove to work and the battery light came on and stayed on. After getting off shift this morning the truck started fine and I drove home. The alternator is putting out 13.8 volts at idle and the batteries are sitting at 12.8 volts. The batteries are only about 6 months old and I have no idea how old the alternator is. Any suggestions on why the battery light is on or what else to test? At what point does the battery light come on? I know it’s not trustworthy but the volt gauge in the truck drops down when starting and then quickly builds back to dead center after it starts. This is on a 1993 F250 7.3idit

 

[Reggie f250]

If it is charging at 13.8 the alternator is working. A quick check would be to disconnect the plug on the alternator with the green wire key on engine off and see if the light turns off. If it does the regulator is going bad. You can replace it and maybe the brushes if they are worn. Or if you don't want to mess with it replace the alternator.

 

[MPatty]

Well...super easy fix...went to pull the plug on the alternator to check the regulator. I found the yellow wire had come unplugged from the spade and was just sitting on top and appeared to be plugged in until pulled on. Plugged it back up and works great. I hate having stupid mistakes but love quick, free easy fixes.