Your alternator is NOT putting out enough voltage to keep up
with the amount being used. This can be casued by: The belt
Generator Light Stays On With Key Off Engine
slipping on the alternator pulley The alternator is going bad. I
Apr 08, 2009 The red light comes on to indicate that current is not flowing in the proper direction. With the engine running at high idle, fan blower & high beams on, put a DVM across the battery. Battery voltage should be about 14.2-14.5 volts. If it is, look for a wiring problem in the generator light circuit. Oct 28, 2007 Ok I've replaced the alternator and the voltage regulator and the generator light is still on when the key is in the OFF position. When the car is running the light is off. Unless someone has an idea as to why the light stays on it is going to have to go to the electrical shop and it will. In order to have the dash light go off charging voltage must exceed battery voltage. A real common problem is a broken wire at the alternator's side plug-in. The little wire. Of the two wires, the large red wire is hot all the time and the little wire is only hot when the key is turned on. The little wire is not a stranded wire. Jun 10, 2017 Re: Ford 3000 Charge Light Staying on I'd opt for worn brushes if you haven't visited the charging system in the last 10 years. My 3000 just got it's first set of brushes on a replacement generator after about a thousand hours, off ebay.
woudl see if the belt is tight and is NOT slipping. If you haven't
bought a new belt lately, its a cheap investment. If the belt is
tight and the alternator light stays on, take the car to Autozone
or Pep Boys and have it checked while on the car. If you have a
multimeter you can check it by seeing how many volts are comign out
of the alternator by placing the leads on the alternator to see
what current is being generated by it. Anythign less than 12 I
would buy a new alternator. Most cars need over 12 volts to 14
volts to operate. Most of my cars run 13-13.9 volts. Also, check
the voltage regulator which is located on the fire wall below the
left windshield wiper. This a cheap part which often fails on that
model.