Help with Summit Racing headlight wiring harness

[DDiMarco]

Per suggestion from several threads I have read here, I purchased and installed the Summit Racing/APC headlight wiring harness, #890030 for my 04. 5. to improve headlight brightness. I performed the installation according to the poor instructions on the package and am experiencing the following: no lights whatsoever, and the relay(s) are cycling at approx one-second intervals. I hooked the stock connectors back up to make it driveable and kept the harness in place. The relay terminals are not labeled and its too cold to wring out the entire harness but that is my next step. Questions: 1) I read some threads that suggest if the computer isn't seeing the proper load, the headlights will not work; is that true? (that really doesn't make any sense to me because the stock headlights use relays and the electrical resistance should be the same) and 2), has anyone had similar problems with their installation? The new harness electrical grounds are against bare metal and I am not mystified by 12 DC circuitry or how relays work. Comments appreciated. BTW, the fit-up of the new headlamp connectors with the DC receptacle is poor, the plastic connector latch is too short to mate with the DC prong.

 

[DDiMarco]

I have done some troubleshooting; the relay(s) energize at 4 volts from a discreet power supply, so they work. The question is "how much voltage is going through the headlight switch in the cab?" The relays are not getting enough voltage to stay energized OR the harness is not wired correctly. Hope to get some time to wring it out. I also checked ground through the harness, its good. Co'mon, there must be some electrical geniuses out there.....