If your system passes the above quick checks, then it is likely something-------------
1....Could be a bad battery but not likely. "New" does NOT mean "good."
2.....Most likely it is VOLTAGE DROP in the ignition harness
3.....Also likely is poor grounding between regulator case and the battery
4.....In rare cases could be a bad regulator
TO CHECK voltage drop, do the following:
GROUND...........Run the engine at "fast idle," and make the following check first with all accessories off, then again with heavy loads, heater, lights, etc, turned on. Switch your meter to "low" DC volts. stab one probe into the top of the NEG battery post
Stab the remaining probe into the regulator mounting flange. You need to stab through any chrome, paint, or rust. What you are hoping for is a VERY low reading, the lower the better, and zero is perfect. More than .2V (two tenths of one volt) is too much and means you have a bad ground
VOLTAGE DROP. The regulator power source is also the voltage sensing terminal. This comes from the battery, through the bulkhead connector, ammeter, ignition switch, back out the bulkhead terminal through the harness, and to the VR. ANY voltage drop in this harness can cause OVER charging.
To check, Hook your meter to "switched ignition." This can be the 'high' side of the ballast resistor, or the blue field wire on the alternator. Turn the key to 'run' but with engine stopped. Again, with your meter on "low" DC volts, stab your remaining probe onto the POS battery post
As in the previous test, you are hoping for a low reading, the lower the better. More than .3V (three tenths of one volt) means you have a bad connection somewhere in that path.
