Mounting a 50” / 40 amp light bar to the roof

[shimmy]

Hi all, not finding anyone who has done this exact set up so curious what folks recommend. I bought a Heretic 50” light bar on Black Friday sale and intended to mount it up on my roof TrailRax roof rack. As I was about to wire up the harness to the dedicated roof plug I realize this is a 40 amp system, and these are 25 amp outlets. I assume the wiring and everything is not suited to handle 40 amps even if I were to replace the fuse (unless I’m mistaken?)

So now I’m trying to figure out how to wire this thing up. I have a harness with everything needed and can expand lengths if i have to. But it will likely have to come in through the roof to a fixed wire setup. Does anyone have examples of doing this? Looks like I will go in through the stock holes where the existing wiring is, underneath the seatbelt trim, and underneath the rear seats to the electrical panel. Are there stock hard mounting points or a bus bar? For the switch… not sure. Would love to reuse a stock switch somehow. The included switch is lame but can use if needed.

Any help appreciated!

Edit: Also for the record willing to just find a light bar in the 25A range for that plug if the juice isn’t worth the squeeze. I prefer low hassle/“stock-ish” setups. Curious what others think.

 

[TheDocAUS]

Hi all, not finding anyone who has done this exact set up so curious what folks recommend. I bought a Heretic 50” light bar on Black Friday sale and intended to mount it up on my roof TrailRax roof rack. As I was about to wire up the harness to the dedicated roof plug I realize this is a 40 amp system, and these are 25 amp outlets. I assume the wiring and everything is not suited to handle 40 amps even if I were to replace the fuse (unless I’m mistaken?)

Correct wiring will not safely handle 40 amps.

The aux fuse box may not be rated to handle that on the circuit as well.

 

[TheDocAUS]

The easiet option is to buy a lightbar rated at 25 amps or below and change the plug to a DTP and just plug it in, like the INEOS lightbar does.

 

[shimmy]

I started taking things apart and believe I can hard wire it directly into the electronics compartment. Would it be appropriate to connect the hot wire to fuse box supply (pictured)? Wondering if it’s possible to reuse one of the EXT switches for the relay…

Confirmed the light uses ~35 amps when running (using the built in Off-road/Electronics menu).

 

[landmannnn]

I started taking things apart and believe I can hard wire it directly into the electronics compartment. Would it be appropriate to connect the hot wire to fuse box supply (pictured)? Wondering if it’s possible to reuse one of the EXT switches for the relay…

Confirmed the light uses ~35 amps when running (using the built in Off-road/Electronics menu).

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I would take the power supply from one of the connections in the busbar that I have circled in red.



Then I would run a wire from one of the INT outputs to the relay you are going to use. Not too difficult if it is INT1 or 2, you can just tuck the wires behind the trim or under the carpet.

If you are feeling adventurous you could drop down the overhead panel and take an output directly from one of the auxiliary switches (to turn the lightbar relay on/off) and feed the wire across the headlining and down the B pillar. That would be a longer job.

 

[shimmy]

I would take the power supply from one of the connections in the busbar that I have circled in red.

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Then I would run a wire from one of the INT outputs to the relay you are going to use. Not too difficult if it is INT1 or 2, you can just tuck the wires behind the trim or under the carpet.

If you are feeling adventurous you could drop down the overhead panel and take an output directly from one of the auxiliary switches (to turn the lightbar relay on/off) and feed the wire across the headlining and down the B pillar. That would be a longer job.

For the bus bar I didn’t go in there since it’s already full, but I can piggy back off of any of the posts in there if it’s all the same.

For the switch using one of the INT aux switches will work perfectly since I don’t have a use for them anyway. Great suggestion!

The harness that came with the light includes a relay and a switch both with three posts. I assume one of the posts is for the red LED, the other is a hot to the relay and the other is a ground? Can I simply reuse the relay’s switch leads to close the circuit with the INT wires?

 

[landmannnn]

For the bus bar I didn’t go in there since it’s already full, but I can piggy back off of any of the posts in there if it’s all the same.

For the switch using one of the INT aux switches will work perfectly since I don’t have a use for them anyway. Great suggestion!

The harness that came with the light includes a relay and a switch both with three posts. I assume one of the posts is for the red LED, the other is a hot to the relay and the other is a ground? Can I simply reuse the relay’s switch leads to close the circuit with the INT wires?

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It looks like the supplied switch is getting the 12v from the battery (red) and feeding 12v to the relay (blue) when the switch is closed.

Since the INT switch already has a 12v supply you don't need the red wire.

Connect the + from the INT to the blue connector and the - from the INT to the black connector.

 

[Glen]

A little late to the party, but a fair number of people report light bars in the position you show (for any 4WD vehicle) end up illuminating the engine hood with an obnoxious glare. Lights halfway back on the roof can use the roof to cast a shadow on the hood, or mount the lights elsewhere, like the bumper, grill or on a bull bar.

 

[shimmy]

A little late to the party, but a fair number of people report light bars in the position you show (for any 4WD vehicle) end up illuminating the engine hood with an obnoxious glare. Lights halfway back on the roof can use the roof to cast a shadow on the hood, or mount the lights elsewhere, like the bumper, grill or on a bull bar.

Yes I could definitely see that - with this rack I have the option of moving it "back" to a 3/4 rack and putting the light there. I wonder if then it would blast in the safari windows. Will report back to see if this is an issue or not. May also be addressable with a dark hood decal which I was already considering.