Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
IMHO, adding relays is a whole additional level of work. In addition to everything he did here, you would have to cleanly wire them to power and ground buses, and mount the relays. Not a trivial marginal addition to this project.
I’m using all the factory aux power for the actual upfitter switches. Only relay I have is one for the rigid radiance backlighting. I wanted it tied to the other amber lights up front and you can’t add even a fraction of an amp on to that circuit. You won’t blow a fuse, it’s monitored by the ECU and will just throw you a code and not turn any of them on. So for that I have a relay directly off the battery and I have it tucked away where those blue wires are for the pass-thru.
I would say that for many people, factory 15a, 10a, and 5a will do for lighting. Baja Designs LP’s are 7.5a draw a piece though unfortunately, so if you want to do that or certain 40”+ light bars you will need relays.
My current setup:
Aux 1: Two (2) Rigid DXL Ditch Lights
Aux 2: Rigid 40” Curved (Amber backlighting on relay)
Aux 3: Two (2) Rigid SL 10” Amber Floods for Fog Lights
Aux 4: Two (2) Rear Rigid Radiance Pods
Aux 5: Future ARB Compressor (Will be on relay)
Aux 6: Maybe a horn or something fun.
I have an idea to buy one of these:
https://www.roughcountry.com/mlc6-multiple-light-controller-70955.html
But instead of using their switches, just splice the upfitters into the switch harness so that the upfitter voltage is the relay trigger for the MLC-6 relays.
After doing this I’d have (6) 30amp fused relay circuits, each with a power and ground point, triggered by the upfitter switches. Add a 2 pin Deutsch connector on some pigtails from each relay, and it’s a pretty clean setup.
I asked Rough Country if they would sell it without the switch bundle since I wouldn’t need it. They said no, but they agreed that it would be a good idea for trucks with existing weak sauce upfitter circuits like our Raptors. If I find one on sale or used somewhere I’ll be giving this a try.
View attachment 159496
I have an idea to buy one of these:
https://www.roughcountry.com/mlc6-multiple-light-controller-70955.html
But instead of using their switches, just splice the upfitters into the switch harness so that the upfitter voltage is the relay trigger for the MLC-6 relays.
After doing this I’d have (6) 30amp fused relay circuits, each with a power and ground point, triggered by the upfitter switches. Add a 2 pin Deutsch connector on some pigtails from each relay, and it’s a pretty clean setup.
I asked Rough Country if they would sell it without the switch bundle since I wouldn’t need it. They said no, but they agreed that it would be a good idea for trucks with existing weak sauce upfitter circuits like our Raptors. If I find one on sale or used somewhere I’ll be giving this a try.
View attachment 159496
I think your idea is genius--if you know you will need relays! I actually have a MLC-6 in a Jeep LJ I own. It's the only product from Rough Country I wouldn't be ashamed to own. The only limitation is that its native design is always on. You leave a switch on--you left your accessory on--and your battery is gonna die. By using the upfitters as switches, you will have solved this limitation because the upfitters are only powered with ignition ON.
Your challenge will be mounting it in the engine bay. Side of the battery box would be my first thought, but I haven't test fitted it. Personally, I am not a fan of mounting to the top of the fuse box. I don't like drilling into the top of the factory fuse box and breaking that watertight design, nor occluding access to the factory fuses. But some people go with that location and have no problems, so you might consider it.
You could do all your Deutsch connectors on a workbench and be able to attach them to the MLC-6 outside the engine bay. Depending on where you mount it, you'll most likely need to extend the upfitter wires. You could go ahead and fit your extensions with ring terminals to attach to the MLC-6 on your workbench, outside the engine bay.
Really great idea! Show us some pics if you implement it!
Not the only limitation. Disclaimer for anyone entertaining this, you will limit your whole system to 50a. Our factory setup is better than this at a total of 60a as all upfitters have their own fuses (15+15+10+10+5+5). This system has a 50a inline breaker so you are limited to 50a total from the battery despite each delay having a 30a fuse on it.
Again, in my opinion this is a downgrade. What does it really get you? If you need a relay or two, just use a relay or two.
Not the only limitation. Disclaimer for anyone entertaining this, you will limit your whole system to 50a. Our factory setup is better than this at a total of 60a as all upfitters have their own fuses (15+15+10+10+5+5). This system has a 50a inline breaker so you are limited to 50a total from the battery despite each delay having a 30a fuse on it.
Again, in my opinion this is a downgrade. What does it really get you? If you need a relay or two, just use a relay or two.