International Full Size Jeep Association

International Full Size Jeep Association (
-   Homegrown Vendors: (Members who produce FSJ related items) (
-   -   Better Relay Headlight Harness For Sale (

Mass 01-03-2019 04:44 PM

Better Relay Headlight Harness For Sale
Finally for sale!

In case you haven't seen the build thread on these...
My upgraded "serehill" harness includes:

- 12 gauge GXL load wire
- 14 gauge GXL "trigger" wire
- Separate fused supply circuits for high and low beam
- Waterproof Hella 40 amp relays
- Delphi (Aptiv) terminals in relay socket and fuse holder
- Perma Seal Molex marine grade ring terminals
- Waterproof fuse holder with a spare fuse
- High temp "gray stripe" nylon wire loom
- Ceramic headlight connectors for superior heat resistance - good for stock or high wattage bulbs
- Plug and play - no cutting into stock wiring - can be reverted back to stock at any time
- I refer to it as a "terminal to terminal" build because I build each one from the ground up without splices on everything. I don't build with "pigtail" components

Here's the "just"

A headlight relay harness is perfect for the weak headlight electrical system in our jeeps.

It takes the load away from the switch and feeds the headlights the best possible voltage directly from the battery or alternator. This gives the brightest and most reliable output from the headlights possible.

It can be used for stock sealed beams or higher performing sealed beam conversions that utilize H4 bulbs. I'm running two 90w/130w H4 bulbs without an issue. The stock wiring would have melted at that wattage.



A little over a year ago when I realized I needed my high beams on to see at night. I knew something was wrong. I also knew from a previous experience exactly what I needed. So I bought a harness on ebay. Complete JUNK! I ended up patching it together with wire and parts I had to make it work right. Shortly after that I joined IFSJA and very quickly discovered a thread started by "Serehill". Everyone has seen it. Its the one about a harness that promised to fix the very issues I and many others are/were having.
I was a little late to the game with his unfortunate passing but something he said stuck with me. His signature says "If you can't make it better why waste your time."
The light bulb went off. Why not MAKE a BETTER harness?
So here I am. A little while later and making what I feel is a superior harness at a very reasonable price.



Due to the high parts costs and time associated with making a quality harness my final price will be $100.
This includes domestic shipping including Alaska, Hawaii, Puerto Rico, Guam, and U.S. Virgin Islands



- If you'd rather hard wire the relay signal wires I will delete the male plug that goes into the OEM female plug and include 3 butt connectors and heat shrink. $5 less making it $95 total.

This is more of a preference you decide when installing.

- Kit is made so you can conceal the "fuse holder" behind the passenger headlight for a stock look or have it in the engine bay for easy accessibility

- Also I left the power wires long enough to go to the battery or alternator. Whichever one you choose will work.



Please ask them!
Feel free to PM if you'd like to buy one




61Hawk 01-03-2019 07:06 PM

Pretty, if I didn't already have one of the Serehill harnesses I'd look to buy one of yours.

Kaiserjeeps 01-04-2019 06:22 PM

Very nicely done. I ended up building one after Serehill passed as I needed one. But if yours was available then I sure would have done it. They look just great being well made and the epoxy sealed terminal choice is stout. By far a vast improvement to the stock headlight circuit. :thumbsup:
And thank you for taking the time to make them and offer them up.

Tripwire 01-04-2019 07:31 PM

I would hate to steal from rick's idea as i think one of his own is still making them? if not is this thing plug and play? can you PM me the installation instructions


Atlasts 01-04-2019 08:49 PM

Looks good
I will order one soon. I would like the instructions now if you can send to me.


Mass 01-04-2019 10:01 PM

Thanks guys! I try and make it look good and use quality components. Those sealed ring terminals are worth every penny. It keeps corrosion out and adds stability to the crimp.

I was under the impression that his son (I think) stopped communicating through the forum.

I made it plug and play unless you want to hard wire it in. In which case I'll take $5 off and include the butt connectors and heat shrink.
In-struc-ti-ons? :confused: What is that?
Nobody will read them anyway :D

Just kiddin.

I'll be doing a write up with pics this weekend if I get a chance but in case anyone is curious it should take about 15-20 minutes to install if you don't have distractions.

Here's a quick run down of installation from memory...

1. remove headlight bezels (4 phillip screws each)

2. remove and unplug headlights (also 4 screws)

3. remove grill (a few bolts, mine also had some phillips screws)

4. route new harness in - The far end with the male and female plugs will go on the drivers side. Plug that male plug into the factory wired headlight socket and the ceramic female will get plugged into the headlight later. Route the fuse holder, positive and negative leads through hole behind and "up under" the passenger headlight area where the battery is. (see pics of the fuse holder above)

5. Attach both positives to either the battery positive or the output stud from the alternator.

6. Attach negative to negative side of the battery

7. You can either let the relays "hang around" behind the passenger headlight or use self tapping screw to attach relays to the header/core support next to the passenger headlight

8. reinstall headlights using the new harness plugs

9. test em out

10. zip tie the harness up and make it look tidy

11. reinstall grill

12. reinstall bezels

13. pat yourself on the back

It sounds a lot more complicated than it is. Once I get the pics you'll see how easy it is.
You'll need very basic hand tools.
No cutting and splicing. I promise.

(Edit) Price includes shipping to the states.

Tripwire 01-05-2019 05:56 PM

PM me your paypal..... a crude wiring diagram would be nice :)

Mass 01-05-2019 08:17 PM


Originally Posted by Tripwire
PM me your paypal..... a crude wiring diagram would be nice :)

Pm sent :)

Mass 01-05-2019 11:41 PM

Here's my crude diagram for those who may want to make their own.

Obviously not to scale or to show component and splice placement. Just a general working schematic.

rscott2214 01-10-2019 06:03 PM

PM me your paypal. I'll take one as well.

Mass 01-11-2019 07:55 PM

PMs returned!

Thanks guys!

bigbadjeep 01-12-2019 04:56 AM

This guy is the real deal folks! I just got my harness, it's as good or better than he describes. Now I need time to install the Hella H4 lights from BJ's with the 90/130 Hella bulbs. Been waiting for these for nearly a decade. Thank you Mass! And I'd like to thank BJ's ordered one day received the order next day! But seriously, on this forum is some of the best collective minds for these FSJs.

BigOberg 01-18-2019 10:16 PM

Looks awesome and I need one. Serehill's Kit was always on my to do list and unfortunately I didn't get to it before his passing. PM sent

Mass 01-18-2019 10:43 PM


Originally Posted by BigOberg
Looks awesome and I need one. Serehill's Kit was always on my to do list and unfortunately I didn't get to it before his passing. PM sent

Pm returned.

Full Size Jeeper 01-19-2019 01:08 PM

Hey Mass, Thanks for making these! I bought all the stuff to make one and I just don't have the time. I will send you a message with all my mailing info and you can give me your paypal or what ever method of payment works for you. It looks great! Thanks, Darin.

Mass 01-19-2019 03:14 PM

Sounds good Darin,
I look forward to your PM.

Don't sit on it too long though! I've only got enough parts to do 2 more harnesses. I'm ordering more stuff this weekend but I wont have it for probably another week or so.

oldjeepman 01-22-2019 09:55 AM

Mr. Mass, Yes I would like one of your headlight harness. Whenever it works for you. I'll send my info in a pm. Can do PayPal. Thanks Randy

Mass 01-22-2019 11:45 AM

PMs returned!

Full Size Jeeper 01-25-2019 06:30 PM

Hey Mass, check your paypal! Thanks, Darin.

Mass 02-08-2019 01:02 AM

PMs sent!
8 more Harnesses are in the mail.

Thanks guys!

All times are GMT -6. The time now is 11:50 AM.

Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.