Charging system voltage high

Make the following checks, and if they show nothing, it's either the regulator or the battery. What you will be checking for is "voltage drop" both across the ground and "hot" side of things.

Get the car running, and jack up the idle to simulate "low to medium cruise." Turn off all accessories.

Take your meter on LOW volts, and stab one probe directly onto the battery neg. post. Stab the other probe directly onto the regulator case, and make sure you penetrate the paint/ chrome.

What you are looking for is a VERY low reading, the lower the better, zero would be perfect. Anything over .2V (two tenths of a volt) shows you have a grounding problem

Now check the "hot" side. What you may have here is a bad connection in the path from the battery -- fuse link-- bulkhead connetor, --through the ammeter circuit -- through the ignition switch connector, the switch contacts, and back out the switch connector -- back out the bulkhead connector.

So stab one probe directly onto the battery positive post. The other probe goes to "ignition run" IE the traditional dark blue which feeds ignition voltage to the ignition system and regulator. It might be that the ballast resistor is the closest you can come.

Once again, you are looking for a low reading, and a difference of more than .2 shows a drop problem in this circuit.

Regulators --that is, electronic ones -- seldom act in this manner. I'm betting it's either the ground or ign circuit that's causing you grief

On my 67, there was a ONE VOLT drop through the bulkhead on "ignition run." This was causing considerable overcharging.

Another way to check the "hot" circuit is to turn the key to "run," engine off. Put your probes on battery positive, and the "ignition run" supply. You are now measuring the voltage drop directly in that circuit.

Also, more and more, we hear of owners with "bulkhead connector" troubles. It might just pay to pull it apart, inspect and clean it, replace any bad terminals, consider feeding the big alternator/ battery feed wires "straight through" and read the "Mad Electrical" article on the subject:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

which came from here:

http://www.madelectrical.com/electrical-tech.shtml