1984 quad headlights draining battery

[84reject]

I replaced my alternator and checked the rear post it is sending out 12.6 volt at idle. Im getting 12.6 volts at the battery too. When I turn on the headlights the stock volt gauge drops to 9. The headlights are very dim and the blinkers wont flash. Turn off the headlights and the blinkers flash and volt meter comes up. What do I check next?

[Marshy]

Check the grounds?

[84reject]

I should have mentioned. I unwrapped the headlights harness and soldered and corrected bad headlight sockets and ensured that harness was grounded.

[Dead Parrot]

Use an independent voltmeter and measure the voltages. Stock gauges tend to get off after several years.

You should have more like 13.5 to 14.5 volts at the back of the alternator with the motor idling and every optional device turned off. Sounds like your alternator isn't charging. Stock or 1 wire? If stock, make sure the two smaller wires have good connections. One of them is the voltage sense wire and the other provides the initial current to start the alternator charging.

[84reject]

Took alternator in for load test. Bad alt out of the box. I'm charging battery back to 100% before reinstalling another remand alt tomorrow. Thanks for input, I appreciate the second opinions.

[84reject]

charged up the battery and installed a 78 amp alternator, guess those Chinese kids did a good job rebuilding it. I can run the high beams and defrost and the stock volt gauge stays steady near 13. Good to go.
Now to finish the fuel system rehab. Fuel pump is on the way out, main shaft of carb is sucking air ect...