So I’m working on my MX7000 light bar. I can’t figure out the wiring. I’m not going to wire the rear hazards because they’re covered by the roof rack. I just want the alleys, front, and top rotators working on three switches.
I have the switches, which are steel 30amp switches. I’m building the box.
Now, I’m trying to wire the relays. This is where I’m confused. I’ve done all the research I can on the site and I still don’t understand the nature of using relays for three switches. I can manage to wire one switch for one relay, but I don’t understand how to chain relays to work with three switches on one 30amp fuse power supply.
Do you guys have a diagram or explanation of wiring three relays to three switches, using one 30amp primary power supply straight from the battery?
Here’s my current understanding of how it works. Does each relay need its own 30amp fuse on the + terminal leading to the battery or can all three relays be split from the same wire with the one 30amp fuse?
Also, one simple question. Have any of you managed to hide the power cable without drilling a hole? I don’t think my Jeep Grand Cherokee has any gutters. I’m afraid I’ll have to drill a hole in top to feed the main wire in. I just don’t know where to drill it. I guess directly below the bar, hidden near the luggage rack, which will let it feed down the driver side and below the seat…Any opinions or suggestions on this?
OH YEAH. I also need a pair of amber top lenses if anyone wants to part with a set.
There is no need to use relays for this lightbar. 30 amp switches can easily handle the load. Run one 8 gauge or larger wire from the battery to the switch box with a 30 or 40 amp fuse (fuse should be less than 18" from the battery). The penetration through the firewall or any other metal surface MUST be run through a rubber or plastic grommet and sealed with silicone. Connect three wires to the power wire, connect one to each switch and then connect the lightbar cable to the switches. The lightbar ground wire should be connected to the chassis of the vehicle. Be sure to scrape the paint off of the area where you connect the ground.
As for routing the control cable, if possible, drill a hole directly below the point where the cable exits the lightbar housing. The cable should run straight down instead of across the roof. NOTE: there is a metal beam that crosses the roof at the “B” pillars. Do not drill through the beam! The hole should be 3/4" or 1" in diameter with a rubber grommet and sealed with silicone. Before drilling, pull the headliner down a little bit and put something in there to hold the headliner away from the roof. This will help prevent drilling too deep and going through the headliner.
I recommend putting the switchbox in the back of the vehicle, where it’s not possible to reach while the vehicle is in motion. It’s very tempting to use your lights when road rage kicks in or when you want to freak out your friends. Get rid of that temptation and cover you butt! It may be a bit inconvenient , but it will make your life a lot easier if a cop questions why you have a lightbar. I’ve seen people get slapped with HUGE fines and their equipment ripped out (without care) and confiscated.
I hope this helps. Let me know if you have any other questions.
Thanks for the reply. The only issue I have is that out of everyone I’ve talked to, you’re the only one who doesn’t think a big lunky Mx7000 is okay to run without relays. This thing is huge and tasking.
Have you personally done this? Not trying to sound off, just honestly curious.
As for the legality issue. I don’t have road rage issues. I’m cool-headed and I don’t screw around with cops or people. Also, I live in Texas. Technically, no private citizen ‘should’ need a light bar mounted, but they have quite a few exceptions. It’s actually pretty common to see private contractors mount amber bars. The guy I bought it from does that very thing, along with a few actual illegal mods to his truck under the hood. I’ve also seen plenty of guys mount bars while hauling ATVs on trailers just to drive to the river near by. The common suggestion is to just never mount blue or red, and more recently, white(local sheriffs have started using white).
Like most places, I think it really comes down to what you’re doing with them. If you’re driving with the lights on in traffic, then you SHOULD have your set ripped off the roof. You’re being a ■■■■■■■ and you’re trying to push people around. You can cause accidents and all sorts of problems.
The only time I would run the lights is when the vehicle is parked on private property or in a parade…Which is what most everyone else does with them.
Dave (Haint) works for a place called Macon Communications which does the installations for several local law enforcement, fire, and emergency agencies.
He also did ALL of the wiring for my current light rig on my Ecto…so I can totally vouch for him.
I’ve installed thousands of lightbars over the years. If your switches are rated at 30 amps each, there is no need for relays. The lightbar draws less than 30 amps total, and you’re not even running everything through just one switch. The halogen rotators draw the most current, they should be in the ballpark of 15 to 20 amps. The alley lights should be around 3 to 5 amps. Since each of these are less than the 30 amp rating of the switches, there’s nothing to worry about.
As for the switchbox placement, I was just making a suggestion based on years of experience and intimate knowledge of Georgia law. By being able to prove that you can’t get to the switches while the vehicle is in motion, you’ll save yourself a lot of heart ache should you get pulled over and questioned about the lightbar.
I see. Thanks for the help! I have a question. So If I disregard the relays, the wiring would be to run a hotwire from batter w/fuse that splits into three wires for each switch? In that set up, I don’t know what to do with the stripes wires. I know the ■■■■■■■■■ cable grounds to the car. What about the stripes wires?
The installation manual is extremely vauge. It states, “NOTE: Wiring Colors May Vary, Refer To Wire Tag For Exact Colors.”
My sugestion is to ground the lightbar, then touch each wire to 12 volts and see what lights up. If there are any other black wires (solid or black with a stripe) do not touch those to voltage. These tend to be ground wires for additional options on the bar. If you would like, you can send me some pictures of the cables (with outer insulation stripped off just a bit) and the actual connections inside the bar (remove lenses first). I’ll be more than happy to help figure out which wire goes where.
I’m trying to figure out the set up to just wire the four top rotators for now. The two red wires control the four rotators. If I hold the striped red to the neg terminal and the red wire to the pos, all four rotate normal speed. But, if I touch the large black ground to the jeep, the two center rotators stop.
If I touch both red wires(striped and solid) to the positive and then ground the large black wire to the jeep, the four rotators spin in pursuit speed. Holding both reds and positive blue to the positive terminal with the large black cable grounded makes all five top lights spin in pursuit mode.
Really, I just want to be able to have the top four rotate normal speed while still grounding the bar.
I know the problem I’m running into are the multi-speed capabilities of the bar. I just want the four to rotate normal speed, but with the only setup I’ve figured out, I won’t be able to ground the large black cable(it stops the two center rotators).
From what I’m starting to gather, the main colored wires are power wires, while the striped wires control pattern or speed functions, and the large black cable grounds all of them?
Here’s a post that I found on another forum. It was written by a Code 3 technician. Unfortunately, wire color will vary depending on which technician assembled the bar. There is no standard wiring diagram.
"If I had built this bar, it would be wired like this :
red - outboard rotators
blue - inboard rotators
red/blk - strobe main power (rear)
green - strobe control, alternating mode (red/blk must be powered, adds fronts)
green/blk - strobe control, pursuit mode (red/blk must be powered, front only,kills rears)
yellow - driver alley
yellow/blk - pass. alley
white/blk - intersections
blue/blk - center takedowns
orange - flasher power, alternate (your center rear)
white - flasher steady burn
orange/blk - not used (normally for outboard takedowns)"
Unless someone rewired it, black is ground. If you haven’t already tried it, touch the other wires to positive one at a time & see what you get. If you need any further help, text me some pictures of the inside of the lightbar. PM me for my number.
