Re: Ongoing charging issues

Posted by HH56 On 2023/4/5 9:01:41

Basic charging circuit operation is the same whether positive or negative ground. What happens if you momentarily short the generator field wire to ground?

Have a meter connected across the battery to measure generator output just as before and have the car at a fast idle. During the test it would also be a good idea if all accessories and doors were shut so bulbs are off.. If it is still reading around 6.4 volts instead of the wanted voltage of around 7.4v use a short jumper wire with one end connected to ground and MOMENTARILY touch the other end to the FIELD terminal at the regulator. Make sure it is the field terminal you are shorting.

As soon as you make the connection the generator output should immediately jump up to maybe as high as 9 or 10 volts. Only keep the test jumper connected the short amount of time it takes to read the meter. If nothing changes suspect a problem with the generator but do the same test at the Field terminal on the generator itself to rule out a bad connection or broken field wire. If the voltage does jump high then the problem is the regulator. If no change with either test, the generator is suspected.

Another thing is to make sure the generator and regulator are hard connected so they are both referencing the same ground and not being connected thru various pieces of sheet metal. There is a wire connecting the generator case to one of the mounting screws holding the headlight terminal block on the left fender. From that same mounting terminal on the fender there are other wires but the one in particular to check is the wire that goes to the ground terminal or one of the mounting screws on the regulator. That connection needs to be in good condition so the regulator is sensing the same voltage as the generator.