Relayed headlights - strange behavior - (removed) is going on?
Posted: Sun Jan 25, 2009 9:47 pm
I finally got around to relaying my headlights. The car already has 135k on it and I can't justify spending the $$ to put in HID's, so I got a nice set of ultrabright H4 bulbs, and went to work. I installed 10ga wiring right from the alternator to a pair of relays I mounted where the intake air muffler was (behind DS headlight, next to the battery on the fender wall). I got two new female ceramic plugs for the headlights, and have those switched off the relays. Relay current comes from a male H4 connector I wired to the DS headlight socket (that way I could restore it to stock later on if necessary). My thought was, when the headlights were receiving current from the respective pin on the connector, it would switch the relays and operate the lights that way. I've noticed an increase in performance, even on the lower-wattage filament of the bulb. But here's the rub: When it's hooked up right, when I turn the headlights on at normal brightness, I get both filaments on. When I turn just the brights on, it turns on just the lower filament. When I invert the wiring, so the relays are backwards (lo is hi, hi is low), I can operate the switch backwards and it works okay (where my "brights" are on, they are actually my low beams), but the blue light on the dash is on, but very dim. This has to have something to do with the damn DRL box under the driver's side dash. I already have the yellow wire grounded to disable the DRLs. Is there a diode and resistor I need to stick someplace to fake a load, now that the relays are taking the place of the stock light harnesses, and they draw hardly any current?