Recently, we moseyed over to the Bob Bondurant School of Driving in sunny Chandler, Arizona, and did some high-speed driving in the not-so-sunny darkness of nighttime to demonstrate the importance of vision. Needless to say, the cones were flyin' when we shut off the headlights and got Bondurant's big Crown Vics crossed-up and backwards. Back home, we couldn't help but notice that our '65 Buick wagon's headlights were so dim that driving it at night was similar to our driving experience at the school. Remembering that we hit everything but the timing shack at Bondurant, we called Mark Hamilton at M.A.D. Enterprises for some headlight help on the Buick.
The ol' Buick's headlights were at death's door. We plan to swap in some high-zootin' bright beams in the future, but first we needed to get decent voltage from the alternator to the lamps. Taking a reading from the BATT stud on the back of the alternator, the voltage was a healthy 14.20 volts with the engine at 2,000 rpm.
We also took a reading from the connector at the sealed-beam headlight. The lights were dim because the low beam had only 10.84 volts at 2,000 rpm. The voltage drop was roughly 4 volts. Bogus.
M.A.D. Enterprises sent us a handy kit that routes voltage directly to the headlights by way of a relay. The kit eliminates the voltage-sucking factory routing that takes the current on a journey through the fuse box, headlight switch, dash harness, dimmer switch, and finally through the headlight harness and back to the front of the car. What was GM thinking?
To install the kit, we simply needed to flip on the lights, find the low-beam power wire in the headlight harness, and route it to the white No. 86 terminal on the relay. The red wire connects to the buss bar on the radiator-core support that showed 14 volts (the battery will also work, but it doesn't look as good), the black No. 85 wire is grounded, and the blue No. 87A wire connects to the headlights. The wiring diagram shows the new, improved system that provides a direct circuit from the power source to the headlights using the headlight switch in the car and the high/low-beam switch to trigger the relay. Neat.
We mounted the relay on the firewall and wrapped the wires back into the harness using some black electrical tape to make the job look professional. Note that we used only one relay; there is another relay in the kit that can be wired to the high-beam switch in the same manner. When both relays are installed, the low and high beams both receive the benefit of full voltage. M.A.D.'s relay kit costs around $24 and includes the two relays, directions, and all the wires and shrink wrap needed to support headlights, fuel pumps, electric fans, or any 12-volt gizmo you scored at a swap meet. Come to think of it, Freiburger's '62 Biscayne needs a set of air horns and a light-up hula girl.
Well, here we are. Look at how happy we were when 14.14 volts appeared in the volt-meter window when we measured the headlight voltage. Hamilton says a 10-percent voltage increase results in roughly a 30 percent increase in brightness. Now we can see what's really going on when we drive down the freeway. Or maybe we don't want to know.