Introduction: How to Mount and Wire a Light Bar
The ultimate video guide on how to mount and wire an aftermarket light bar on your vehicle. This particular tutorial was done on a 1998 Ford Ranger with a custom hidden grill mounted bracket. While you can use the supplied wiring that came with the kit or an aftermarket wiring setup, my wiring guide is completely from scratch. I did rough out my plans with some basic measurements to determine if this would work and draw up a rough 3d sketch on AutoCAD. I will make the plans available for this project on my website for free as a PDF.
- grinder with disks
- paint marker
- light bar
- welding shield
- welding jacket
- welding gloves
- chipping hammer
- wire brush
- tape measure
- nutcert tool
- fasteners and hardware
- ratchet with socket set
- wax and grease remover
The front end of the truck did need to be disassembled. I marked out the rough location of the grill using a straight edge and tape to have a reference point to save me from removing or reinstalling the grill. The grill on this particular truck is held in with four bolts along the top and snaps into two clips on the bottom just above the bumper.
I could have drilled two holes in the bumper, but to be honest I’m not a fan of that method. For this I can give the truck a one off custom look and drilling the chrome bumper is not only hard as the chrome plating is quite tough, but this will jeopardize the chrome plating eventually. Once you penetrate that chrome plating, this opening up for rusting or peeling.
Now for the material, it good to order a little more than you actually need. I went to a local metal supplier, gave them a list of material that I needed, and here it is. If you find a metal supplier or machine shop, purchasing the material will most likely be much cheaper than shopping at a big box or hardware store.
I have schedule 40 1” diameter pipe, 1” 90 degree bends which I’ll explain why I went that route in a moment, 1 1/4” by 1/4” flat bar, and 1 1/2” by 3/16 flat bar.
Everything will need to be cut to size. Mark out the cuts with a paint marker first and then use a scriber for the exact measurements. Use an angle grinder with a cutting disk, cuts may need to be squared up with a file or grinder and grinding disk.
For this I have used a flux core mig welder, this is a great project for perfecting your welding skills if you are new to welding. Tack welds are needed first to hold everything together, than beads can be ran after. Welded joints are chamfered to help with penetration, reduce distortion, and keep the welds down.
Painting options will vary depending on your personal preference. For prep, wipe the pieces down with a wax and grease remover so there will be no contaminants when sanding. Depending on what type of metal is used, you’ll need to remove any existing coating whether it’s a paint, oxidations from manufacturers, slag, or whatever else that may effect the final finish.
I used some abrasive pads and then finished up with 220 grit sandpaper before the primer stage. Using a handheld sander allowed me to remove any sharp edges or burrs, a file can also be used if you wish.
Give the pieces another wipe down using a wax and grease remover, ensure they are clean and free of any contaminants.
For primer, I did explain basic rust repair in an older video, so I won’t get too far into depth here trying not to repeat the same information. Using a filler primer will allow you to hide light imperfections in the steel surface. Steel from manufacturing may have some dimpling, scratching, or other forms of imperfections so you can hide them if you wish.
Apply the primer, it’s important to work in a well ventilated area and wear a respirator.
Pick a color and finish of your choice, for me I’m going with a gloss black. The bar will remain subtle, easy to keep clean with a smooth gloss finish, and matches a black truck. Apply the paint, when finishing up the underside it was tough as I didn’t want to leave this for the next day. So I ended up installing a bolt, wrapped a hard wire around that bolt, hung it up and applied paint to the bottom side.
Unfortunately the diffuser does not clear the bracket that bolts to the radiator support, so it will need to be notched out. I roughed in the area using a marker and square. Using a square to create a symmetrical cut.
Next using a hot knife I was able to create a clean slice in the plastic. I had to do a couple test fits and make adjustments accordingly as the plastic isn’t totally square.
Once satisfied I cleaned up my cuts with a fine file. The vertical cuts were about 1.5 inches and the horizontal cuts ended up being about 3/4 of an inch.
Finally I can reinstall the plastic diffuser which installs in reverse of removal. Make sure those push clips are seats correctly.
Install the tube frame with light. I have left the light on this, just personal preference. I used the foam packaging supplied with the light bar to help hold it into place. Applied some threadlocker to the bolts and flat washers as well. It may seem like a tighter space to work, but it’s not any worse than working on a starter motor. Just be careful around the radiator, not to damage the fines.
The wiring is done completely from scratch. While Auxbeam does supply a great wiring kit, the wiring I have installed is customized for the vehicle and closely matches the stock wiring for a clean design. It also has room for expansion if you wish to add more lights to your vehicle.
- fuse holder
- weatherproof connectors
- spade connectors
- eye connectors
- soldering iron and solder
- heat shrink
- heat gun
- wire casing
- zip/cable ties
- wire cutters/stripper
Weatherproof connections are used to help keep water or moisture out of the connection so we don't have a failure in the future. Special crimpers are needed to install these weatherproof connectors. For wiring, a wire gage chart is needed to determine what gage wire is required. This is based on distance and light amperage. Undersized wire can cause a voltage drop and overheat being a hazard for a potential fire.
An aftermarket fuse box was installed on a bracket, this is much easier than tapping into the vehicle's stock fuse box and looks cleaner than an inline fuse. Most importantly, we have room for expansion, this box can take up to four fuses.
For crimp connections, I have removed the plastic case and installed adhesive filled shrink tube instead. Personally I think this looks cleaner and if you push it pads the wire strained, this will help seal the connection.
A wire will need to be ran inside the cab, along with a switch. For this scenario I am using a switched ground which keeps the power out of the cab and less wires need to be ran. I used a step drill to cut a hole in the firewall, then installed a rubber grommet.
Disassemble the dashboard as required, ensure there is enough room behind the switch. Drilling the hole in the dashboard can be a little challenging if you don’t have a large enough drill bit for the switch. I used a wood spur bit instead, covered the surface in tape as protection and then cut the hole. The spur bit did a clean up in the plastic. Unfortunately it needed to be slightly larges so I used an abrasive bit t open it up slightly.
The main power wire, I left this to the last. The battery terminal clamp has tangs on the side to hold on the bolt. I bent those back, popped the bolt out and inserted the main wire which powers the new fuse box. Some vehicles do have a main power bar to tap off of, either under the hood, in the cabin, or in the trunk space. This does not, so instead the battery is the main hook up.
Once everything has been finalized, use some small zip ties to tie off the new wiring so it doesn’t interfere with anything and has a clean look.
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