Help with Headlight Harness and 4HiMOD.

[davkenrem]

I have known about the High Current Headlight/ 4High Mod for a long time. I built a harness 7 or 8 years ago for my 1999 z56 Tahoe. When I junked it this summer after finding a clean K1500 Suburban, I pulled the harness and other goodies from it before getting rid of it. I recently re worked it lengthening it to reach the firewall with the relays rather than up front with the battery. I also replaced all three relays with new ones.

One thing I never quite figured out with this harness or the old one is where to place the diode to prevent back feeding the High Beam indicator when only the low beams are on.

Here is my basic wiring diagram

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I believe the diode should go between 86 on the low beam relay and 87 on the combo relay.

Does anyone see any issue with this. I plan on using this diode.

https://www.radioshack.com/products/3-amp-200v-barrel-diodes

Thanks in advance.

 

[21Actual]

I did the 3 relay method on both my trucks to achieve the 4 hi effect without using a diode. No issues with back feeding at all. Ill try to find the diagram I made for myself.

 

[21Actual]

Found it. This is how mine is done on both trucks.

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[GMRedline]

You shouldn't need a diode with 3 relays.

http://www.gmt400.com/forum/showthread.php?26497-Heavy-Duty-Headlight-Harness-and-4-Hi

 

[davkenrem]

Reworked myharness this morning with your imput and it works great, thanks for the help.