erock13

Makin a new wiring harness for my headlights, cant get it to work though.. Rt now just workin on the low beam, but I have pin 30 on my relay being fed power through a fuse link, pin 85 going to the original lights ground, pin 86 going to the low beam feed, and pin 87 going to the top post of the h4 plug, which is the low beam power, and the left post going to a ground, and the rt high beam post wire just dangling for now.. I thought that was correct for switched ground, no? tried switchin 85 and 86 around too, nothin..

Michael Beckman

You need to connect the ground from the original headlight harness to the ground on your relays. I had the same problem when I built my harness. I used the passenger side headlight plug, then split that ground to each of my relays.

erock13

iT is the ground off the stock harness, still cant get it to work though.. double checked and made sure all the wires were labeled correctly and they were.. 30 to power, 85 to harness ground, 86 to harness low, and 87 to bulb low, and bulb common/ground to battery ground.. Dunno whats wrong..

Sturmcrow

Have you tried a different relay? Are you using genuine Bosch? Does the relay "click" when you put power across 85 and 86?

erock13

Not a bosch, but Yes, the relay clicks, even swapped it with one of the relays for my auxiliary lights, worked fine.. I think i got one of the wires mixed up, ill have to check and play with it again tomorrow though cuz i work graveyard so i had to reconnect the stock wires back up so i can have lights to get to work..

erock13

I royally suck at wiring and gave up.. SO I just bought a harness, and it, half works.. For one, it IS a switched power, I thought that the only thing that would not work correctly with a switched power harness is the high beam indicator light unless you added a diode, or is there more to it? Because its all connected, even sanded off the grounds and made it nice an d bare, but I can only get the passenger side to light up, and thats only if I keep the stock plug inserted into the drivers side bulb, if i take the stock plug out of the bulb, the drivers side shuts off.. And when I put the harness plug in, it still does nothing.. So passenger side harness plug works, but only if that stock plug is connected to the drivers side bulb.. Any suggestions?

abecedarian

Let the harness turn the relay(s) on and off. Let the relays switch power from the battery to the lights.

RAD4Runner

Correct. Harness will connect to stock connector that plugs into one of the bulbs. Stock connector has one pin that provides steady 12V to both HI and LO filaments when headlight is on. Two other pins get ground (hence, switched-ground) from dimmer-combo switch. These pins when connected to conversion harness will turn on either HI or LO relay.

Get a Switched-ground harness.

1. When dimmer-combo switch is in Low or High Beam, there will be constant + 12V to positive side of BOTH relay coils
   
2. When in low beam, low beam contacts of dimmer switch will connect negative side of low beam relay coil to ground, turning that relay on.
   
3. When in high beam, high beam contacts of dimmer-combo switch will connect negative sire of High beam relay to ground, turning that relay on.

4Crawler's site has a schematic.