Short Version: Charge Light flashes while running. Started this morning, STOPS running when any major elecrical draw(lights, horn, wipers) activated.

Long version: Never had problem in the three years I've owned the truck. Alternator/External Voltage Regulator both look pretty old. Wiring looks OK. Alternator is putting out 15 volts. I changed the starter relay a week ago and up 'till today NO PROBLEM. Truck runs fine otherwise.

I refered to my Chilton manual and it states the light will activate(steady on) if there is no voltage and will also activate if there is an "over voltage" problem. Light will activate when ignition switch is in RUN position(engine OFF) as normal then go off when engine is started. It will remain off for approximately 15 seconds then it will start to flash, under the conditions stated in the post.

As I am no expert , I believe there is an OVER voltage problem which causes the light to activate THEN, when an additional draw is added, the voltage decreases and light goes out.

As soon as the extra draw is shut off, the light goes back to flash.

I removed the voltage indicator lead from the alternator and the light stays ON steady, when I replaced the lead it NO flash for 15 sec then it flashed again.

I am thinking voltage regulator OR alternator. What think you?

THANKS FOR ANY HELP.

Ken

 

15volts charging is a little high. 14.5 is about the limit. Sounds as if the regulator is failing. jd

 

the charge light is a simple voltage difference mechanism. one side is battery hot. if the alt voltage drops lower, current will flow from battery (+12) to whatever it dropped to. the difference will be the voltage available for the light - they start to light up around 5v, whereas a trume flameout give a nice bright 12v light.

Im thinking the regulator/diodes need peeked at.

 

This is an intermittent problem, so it may be hard to find. The first thing I would do is pull the plug off the regulator and make sure it and the regulator terminals are clean.

Especially look at the "A" terminal with the yellow wire. This is the wire that tells the regulator what the system voltage is. If this has a bad connection, then it will give the regulator false info and may make it overcharge. I believe this wire goes to one of the solenoid terminals, so since you disturbed this area, it would be worth looking at carefully.