So, I decided to build a relay harness for my headlights. I've heard people have had good luck with getting more light output so i decided to give it a go.

 

With the harness installed, only the driver headlight works. It looks much brighter, but one light wont cut it! LOL. High and low beam have the same result. The high beam indicator is on with the high beams but goes off with the lows, like its supposed to. 

 

I used the Low+ and Common from one side on the relay for the low beams, then I used the High+ and Common from the other side to trigger the Highbeam relay. The reason I used the common from the OEM harness is these headlighs are 99% of the time ground switched/triggered systems.

 

Anyone have any thoughts as to why I only have one light lit? Relays are confirmed working, Wiring is soldered with verified continuity.

 

 

Thanks,

Travis 

I set mine up two power on both lights from the driver side pigtail. since it's only sending enough voltage to close the relay it's not straining the fuse or switch and a whole lot simpler to troubleshoot. that aside your passenger side fuse is probably shot.

Fuse is fine...I unplug the harness and the lights work as normal, and it tests fine. I'll give the single side approach a try. You are right, far far less current than a light running on it. Also, I'm thinking since its ground switched maybe the switch is expecting to "see" both filaments resistance. I'll give it a try.

 

Travis

I think I recall running into that when i first dabbled with this. ground switching has it's quirks. one of my relays died and it created an unusual effect with the high beams.