Too much voltage to headlights?

Worth repeating "I guess."

ANY voltage drop in the path between battery and VR will cause overcharge/ over voltage even though the VR is correctly operating.

1....If there is ANY voltage drop between battery NEG post and the VR ground (mounting flange) whatever that drop is will be added to the charging voltage. That amount of drop WILL be affected by other car powered circuits sharing the same ground path. "That is" if say, the only path is a dirty, loose ground jumper between battery NEG clamp and the body, if there is 1/2 volt drop there, then 1/2 volt will be added to the VR set point and the battery will "see" 1/2 volt high from 14 nominal

2...If there is ANY voltage drop in the hot side, each point at which voltage drop is generated ADDS to a total which will cause that overcharge voltage. The path, generally, for stock vehicles is Battery POS post---to starter relay big stud-----fuse link-----bulkhead connector (RED ammeter wire)-----to the ammeter----out on BLACK ammeter wire----to welded spice------to ignition switch connector----through switch---out igntiion switch connector on DARK BLUE "Ign1" run wire-----back out through bulkhead connector---------to ignition ballast and branch off to VR

So add up each separated point, each terminal, the switch connector, the switch, the bulkhead (twice) and so on.

HOW TO CHECK for voltage drop. There are a couple of ways. How I do this:

A....Turn key to "run" with engine off. Stab one probe of voltmeter into top of battery POS post. Connect other probe as close as possible to VR IGN terminal. DO NOT disconnect any wiring. You will read a small voltage, the smaller the batter. Anything over .3V (3/10 of one volt) check into why. Chase it down and find where its coming from. In the case of either connectors or ign switch, IT CAN CHANGE due to changing "bad connection."

B....Ground.......Run engine at fast idle to simulate "low cruise" RPM. Run this check first with all accessories off and again with lights, heater, etc operating. Stab one probe of your meter into top of NEG battery terminal. Stab other probe into the mounting flange of the VR. Again, the less reading the better. Zero would be perfect. If much of anything reads, improve the grounding between battery, block,and body