Toyota FJ Cruiser Forum banner

RESZ Fab Lightbar Install (w/Roof Connector)

2276 Views 4 Replies 3 Participants Last post by  endus
Despite the tremendous amount of information available here, I still had some difficulty in completing my light bar project so I wanted to post what I did/what supplies I used/how I did it to help anyone else struggling with this.

My main issue was a waterproof connector for the roof. Going through the rack seemed like a good, clean option, but I really wanted to be able to remove the bar if need be. There have been countless threads on this here, but I didn't really find a lot of resolutions for people who were unable to locate the OEM connector and didn't want to buy the stock light bar package just for the connector. If I was smart, I would have ordered the parts from Briareos' post linked below and been done with it.

Briareos' Pictures:

Briareos' Amazon Links for the parts he ordered:

The problem is that I wanted some different options. Black or gray instead of green for color, 6 pins instead of 4 to potentially wire backup lights, etc. I attempted to work through the Amphenol datasheets and's impenetrable catalog to find what I wanted. What I did was order a lot of useless, expensive parts. Mouser's support was useless. I don't recommend them.

It was starting to look like I was going to have to go with Switchcraft, since it was actually possible to find the parts I wanted. My concern was that, living in the Northeast, snow, cold temperatures, and removing snow from the roof of the truck is a reality. I worried about the plastic on the connectors cracking. As I was researching I saw some references to Digikey as another site selling this type of stuff. I emailed their support with my specs (Cable end and bulkhead connector, at least 10A per pin, black/gray, aluminum, waterproof, gasket, cap for bulkhead end, solder cups capable of handling at least 16ga wiring, etc.)

Digikey got back to me saying that their Amphenol stuff was drop shipped from the manufacturer and thus not returnable, but there was a Harwin connector which was more or less the same thing. Their support was *extremely* helpful and clear. I *do* recommend them. Here are the exact details of the connector I used.

Commercial MIL-DTL-5015 Specification

952-1621-ND Cap
C90-25043-14S Harwin Inc. | Connectors, Interconnects | DigiKey

952-1645-ND Free Hanging End (female)
C90-3106F14S-6S Harwin Inc. | Connectors, Interconnects | DigiKey

952-1636-ND Bulkhead Mounted End
C90-3102R14S-6P Harwin Inc. | Connectors, Interconnects | DigiKey

I ordered these connectors and was happy with what I got (finally!)

The next issue was that the harness that came with the light bar (I ordered it as a black Friday special with the lights) had the wires running outside the bar. I wasn't satisfied with this. I got some 1/4" rubber grommets from the hardware store and clipped off the connectors. I drilled holes in the bar using a step drill. I won't go in to the nightmare that followed trying to wire it, but needless to say it involved several iterations of ripping the wires out and redoing it. My tips for this are...

1.) Get a very small gauge very stiff single conductor wire to use as a snake to pull the other wires. Once I found this in my electrical toolbox, it was much easier.

2.) You have to install the grommets first and then pull the wire through. It's just not possible to do it the other way. Lubricate the wire with Vaseline when you're pulling it.

3.) Carefully plan how and where you're going to join the wires from any of the bars you want to come on together. I wanted the two side (flood) bars to come on together, and then a separate switch for the spot bar in the middle.

In the middle of all this I also said to myself, "why can't regular Joes like me buy multi conductor wire for a really clean install? No one sells it!" Well, they do sell it.

This cable is massive overkill. It has twine wrapped in with the wires to strengthen the cable, which makes it fatter than it needs to be and makes everything more difficult. If anyone else goes this route, I recommend finding cable that is also oil/waterproof, but is not strengthened like this.

Once I decided to use this cable, I had to go up to a 3/8 grommet for it to exit the bar and go to the connector. The larger hole made soldering the two flood lights together and stuffing the wiring back into the bar much easier, but I am still not 100% happy with it.

The cable is absolutely as big as the connector I ordered can accommodate. Using the other two pins is not realistic. Another thing to consider is that not using all the pins could impact water resistance because each conductor is individually waterproofed, so stick with the number of pins you are absolutely going to need. I coated the inside of the connector with dielectric grease.

Wiring the connector is also more difficult than it may at first seem. My tips are...

1.) As difficult as it was on the wire I used, you need to get the connector boot further up the wire than you need it to be, and then slide it back down once you finish soldering. The outer insulation needs to be stripped higher up than you might like so that you have plenty of slack when you are soldering the wires into the connector. Trying to only strip a minimal amount of the outer insulation makes it MUCH harder.

2.) With the solder cups facing up, solder the wires at the bottom of the connector first and work your way up. This is incredibly obvious, but it didn’t stop me from doing it the wrong way and making it much harder.

3.) Check, double check, triple check the order in which the various parts of the connector go on, and quadruple check that they are in place before you start soldering. It's easy to miss something and have to undo everything you did.

3.) When soldering, use an iron with a small pointed tip. Strip the insulation off the individual conductors and tin the ends as carefully as you can. You need the strands to really stay tight together so they fit all the way into the solder cup. If any strands (or solder) bulge out, it can short against another pin of the connector. Tin the wires, flux the cup just a little, insert the wire, and just use a *tiny* bit of solder on the iron to conduct the heat. It's too small in there to be sloppy.

After many attempts, I finally got this done. I then wired the bulkhead side, which was trivial in comparison.

Once this was done, I drilled the roof hole. I also made an aluminum backing plate to help spread the load around the roof. I used a spring loaded punch and metal-specific drillbits for the small holes and to start the big one. I used a step drill to finish the big hole. QUESTION - no matter how careful I am, I can never ever drill holes in metal that aren't a little off and need some enlarging with the drill to make them fit. Is there a trick to this? I used the punch while the connector was on the roof, made sure it was centered in the holes, did one hole at a time and put the bolts in as I went, etc. but some of the holes were still a little off!

Another tip – I used the 3m body sealer recommended by the factory instructions for the Toyota light bar. Applying this to the outside didn’t go so well – the gasket that came with the connector got pushed out. I wound up using it around the inside instead.

From there it’s pretty standard stuff. Carlin switches and hella relays from OTRATTW. I also used the connectors they offer for the backs of the Carlins and the connectors that mate with the Hella relays. My boat was wired without the connectors on the back of the Carlins, and it’s a real pain in the butt. Highly recommend the connectors. I just crimped the packard terminals with pliers and am satisfied with the job. A few I also soldered, but it wasn’t needed.

I made a little bracket to mount the relays in the driver’s footwell. Leaving excess wire makes it 100x easier to get it all put together, but there isn’t a lot of space in there to be able to wind it up. It’s something that I may revisit.

I took a couple more pictures this morning on the way out. I noticed that the bolts are rusting, which is pretty bad! Haha. Dropping the headliner again is not on my short list of things to do. I am going to have to try and find some aluminum bolts! But you can see the finished deal in this picture. Note the wires running through the bar now as well.


I am attaching the visio of all the wiring for the truck here as well. I went through this yesterday to reflect the changes I made as I went, so if you see something that doesn't seem right, let me know. This should be fairly accurate.

See less See more
  • Like
Reactions: 3
1 - 2 of 5 Posts

I was going to comment just to subscribe for my own reference when I finally wire my roof lights but...

QUESTION - no matter how careful I am, I can never ever drill holes in metal that aren't a little off and need some enlarging with the drill to make them fit. Is there a trick to this? I used the punch while the connector was on the roof, made sure it was centered in the holes, did one hole at a time and put the bolts in as I went, etc. but some of the holes were still a little off!

You can not get a truly round hole with a 2 flute drill bit, or any drill bit for that matter. We machinists use reamers or a single point boring bar for a round hole.

Position-wise, you should always use a pilot drill in sheet metal to start into a center punch if you are not using a proper centre-drill. The pilot drill should be slightly larger than the "web" of the final sized drill bit.

Using bolts as you go is a great idea, but for common sizes we use "clecos" which are a spring type temporary clamp, mostly used in aviation sheet metal when hand-drilling is required.

Lastly, you will never get a great hole from a hand drill. The angle of the drill to the hole WILL change as you attempt to cut through. Not worth a mag drill... I just use the next size up drill bit as a rule for some clearance. I used to be over-precise, and would end up doing things twice. Clearances are there for a reason.


See less See more
  • Like
Reactions: 1
Very well done. Thanks for taking the time to write this. :cheers:
1 - 2 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.