I have a 6 volt alternator and my lights are very adequate. This wasn't always the case however since my onewire alternator didn't charge at low rpm and once charging would kick out at low rpm's (below 2k or so). To fix that I ran a wire from the accessory side of my ignition switch with a tail light fixture and bulb located near the switch under the dash. Other end goes to the inside terminal of two terminals near the charge (or hot terminal) of the alternator. This makes the alternator charge if it's turning.

I also ran a 8 ga. wire from the alternator to the battery wire on
the starter. No problems now.

If the above makes no sense see this;


Good Luck, RR

RonR


1951 3600 with Clark flatbed, T5, 4.10 rear
1970 340 Duster
1990 5.0 V8 Miata (1990 Mustang Gt Drivetrain)
1964 CJ5