MTN2H2O
New member
I recently installed some supplemental lighting to my 2014 LTZ since I work night shift in a rural area. It was difficult finding information on wiring these to be triggered by the high beams of the vehicle so I thought I'd post for others to reference if they decide to undertake. I also have to give credit to AshesToArmor that previously posted his install http://www.sonicownersforum.com/forum/do-yourself-articles/21621-roof-rack-mounted-led-light-bar.html and gave me an idea of how I wanted to proceed. All links below take to the respective parts I used. The LED light bar on the roof is a Rough Country 30" Single beam black edition part #70730 purchased from PDoffroad.com. The 'rally' style round lights installed on the bumper were purchased from Amazon. I wanted the lights to be individually switched and have the options of 1. auto on/off with high beams 2. manual off 3. manual on. This was achieved with the use of a three way switch (also known as on-off-on, single pole double throw, SPDT).
Some concerns of how the roof mounted LED would perform included glare from the hood, light penetration through the sunroof, and wind noise level. Glare does not effect the driver because of the steep pitch of the hood. You can only barely tell that the light is on if you look up through the sunroof, but it is otherwise very discreet inside the car. Wind noise is present, but surprisingly minimal and very tolerable. With the sunroof shade slider closed you can't hear at all.
My roof set-up includes...
Rhino-rack Vortex racks for naked roof
Rhino-rack LED light mounting brackets
Rough Country LED light bar
Both are awesome products and I am very pleased with them thus far. The Vortex racks are virtually silent compared to the Thule square bars I had years back that required a fairing to quite them down. Both are very high quality and appear they will last a very long time. The Rough Country Single Row light bar is very streamlined with the racks and work well together in both fit and function.
The bumper flood light set-up includes the following...
License plate mount for lights
Wiring harness (not included with these lights as was RC light bar)
Round 27w LED flood lights
1" steel flat bar sourced from Lowe's to extend light mounting width so would not cover Chevy bowtie emblem.
I cut the flat bar to the width I wanted. I then drilled holes to mount it to the top of license plate mount for lights through its factory drilled holes. I then drilled new holes for the bolt to mount the actual lights. Once drilled, I filed the rough edges, lightly sanded the surface, painted with several coats of etching primer, flat black paint, and flat clear coat. I then used all stainless hardware to attach. I did have to drill holes into the bumper to mount the hole package. I purchased the car from Michigan where front plates are not required. I previously had the license plate zip tied to the lower grill and it worked just fine. I knew I wanted to mount these lights with as few holes as possible, and also needed to keep the plate since I'd be asking for a ticket here in VA,
Now onto the wiring....
The only change on this diagram is that the power trigger from the high beams comes from a fuse tap rather than the factory harness. I will explain further later. This diagram could be used to build one's own harness. The pre-built harnesses do look a little nicer and consolidate all of the grounds for you as well.
First off the Rough Country light came with a very nice harness for install and has a classy braided sheath housing the wires. The cheapy Amazon lights did not come with a harness so I had to order the one listed above. Both harnesses are pre-wired to functionally work the same. A simple on/off switch that has an indicator light. Both switches were cut from the harneses. There is a blue (trigger to relay), black (ground for switch's indicator light) and white (positive for switch's indicator light. The only wire I used is the blue trigger wire.
I taped cut the white and black wires staggered purposefully so they would look better under the heat shrink. Taped them with electrical tape.
I crimped on a male blade connector and heat shrinked it.
I then pulled three wires through the firewall. It's helpful to label these for ease of identifying now or if ever need to in the future. You will only need two if not doing two separate light setups like I have installed. There is a relay trigger wire (usually blue on harness) for each light's relay and the high beam 'sender' wire which will make the 'auto/off with high beam' function work. I ran through the firewall grommet by cutting a small slit with a knife being very careful to place away from the factory wiring harness. I then taped the wires to a long flat head screwdriver and shoved them through the slit. On both ends of all wires I crimped on female blade connectors and heat shrinked them. I did this on both ends so it can be easily modified in the future, but the engine bay connectors are not necessarily needed if the relay trigger wire from the harness is directly fished through. Plug one of the relay trigger wires into one of the wires going through the firewall and connect it to the middle terminal of the three way switch. I did the same for the other relay trigger wire on the other harness to the switch. Since both switches need a 'manual on' wire and a 'high beam on/off auto' wire, I used a jumper wire between both switch's top terminal and a jumper between both switch's bottom terminal. Plug the other wire coming through the firewall to one of these. It doesn't matter which one at this time. You can switch it around from top or bottom depending on which position of the switch you want to be 'manual on' or 'auto on/off with high beam'. The middle position of the switch will be the 'manual off' position.
(WILL UPLOAD BETTER PIC WHEN GET A CHANCE)
The end of this wire will be routed to the engine compartment fuse box. I melted a small hole the size of the wire to fit snugly by heating up a nail held with pliers. I made sure the entrance of the wire inside the fuse box was appropriate to the routing inside and no relays would get in the way.
I used the micro add-a-circuit that I purchased in this kit. I installed connectors on the wire inside the fuse box so that the wire could disconnected and the cover be lifted easily out of the way for access. The add-a-circuit is added to the 32 fuse spot/left high beam. The factory fuse was placed in the bottom space of the add-a-circuit and a 2 amp fuse was added to the top fuse space for the trigger wire protection. This and the other fuse tap that will be used are installed in the correct orientation for the incoming and outgoing voltage. Hence there is a right and wrong way, but the easiest way for this application happens to be the most convenient. Installing the wrong way will be difficult because the add-a-circuit pigtail will hit the side if the fuse box. Place the micro add-a-circuit firmly into position 32 (left high beam).
Some concerns of how the roof mounted LED would perform included glare from the hood, light penetration through the sunroof, and wind noise level. Glare does not effect the driver because of the steep pitch of the hood. You can only barely tell that the light is on if you look up through the sunroof, but it is otherwise very discreet inside the car. Wind noise is present, but surprisingly minimal and very tolerable. With the sunroof shade slider closed you can't hear at all.
My roof set-up includes...
Rhino-rack Vortex racks for naked roof
Rhino-rack LED light mounting brackets
Rough Country LED light bar
Both are awesome products and I am very pleased with them thus far. The Vortex racks are virtually silent compared to the Thule square bars I had years back that required a fairing to quite them down. Both are very high quality and appear they will last a very long time. The Rough Country Single Row light bar is very streamlined with the racks and work well together in both fit and function.
The bumper flood light set-up includes the following...
License plate mount for lights
Wiring harness (not included with these lights as was RC light bar)
Round 27w LED flood lights
1" steel flat bar sourced from Lowe's to extend light mounting width so would not cover Chevy bowtie emblem.
I cut the flat bar to the width I wanted. I then drilled holes to mount it to the top of license plate mount for lights through its factory drilled holes. I then drilled new holes for the bolt to mount the actual lights. Once drilled, I filed the rough edges, lightly sanded the surface, painted with several coats of etching primer, flat black paint, and flat clear coat. I then used all stainless hardware to attach. I did have to drill holes into the bumper to mount the hole package. I purchased the car from Michigan where front plates are not required. I previously had the license plate zip tied to the lower grill and it worked just fine. I knew I wanted to mount these lights with as few holes as possible, and also needed to keep the plate since I'd be asking for a ticket here in VA,
Now onto the wiring....
The only change on this diagram is that the power trigger from the high beams comes from a fuse tap rather than the factory harness. I will explain further later. This diagram could be used to build one's own harness. The pre-built harnesses do look a little nicer and consolidate all of the grounds for you as well.
First off the Rough Country light came with a very nice harness for install and has a classy braided sheath housing the wires. The cheapy Amazon lights did not come with a harness so I had to order the one listed above. Both harnesses are pre-wired to functionally work the same. A simple on/off switch that has an indicator light. Both switches were cut from the harneses. There is a blue (trigger to relay), black (ground for switch's indicator light) and white (positive for switch's indicator light. The only wire I used is the blue trigger wire.
I taped cut the white and black wires staggered purposefully so they would look better under the heat shrink. Taped them with electrical tape.
I crimped on a male blade connector and heat shrinked it.
I then pulled three wires through the firewall. It's helpful to label these for ease of identifying now or if ever need to in the future. You will only need two if not doing two separate light setups like I have installed. There is a relay trigger wire (usually blue on harness) for each light's relay and the high beam 'sender' wire which will make the 'auto/off with high beam' function work. I ran through the firewall grommet by cutting a small slit with a knife being very careful to place away from the factory wiring harness. I then taped the wires to a long flat head screwdriver and shoved them through the slit. On both ends of all wires I crimped on female blade connectors and heat shrinked them. I did this on both ends so it can be easily modified in the future, but the engine bay connectors are not necessarily needed if the relay trigger wire from the harness is directly fished through. Plug one of the relay trigger wires into one of the wires going through the firewall and connect it to the middle terminal of the three way switch. I did the same for the other relay trigger wire on the other harness to the switch. Since both switches need a 'manual on' wire and a 'high beam on/off auto' wire, I used a jumper wire between both switch's top terminal and a jumper between both switch's bottom terminal. Plug the other wire coming through the firewall to one of these. It doesn't matter which one at this time. You can switch it around from top or bottom depending on which position of the switch you want to be 'manual on' or 'auto on/off with high beam'. The middle position of the switch will be the 'manual off' position.
(WILL UPLOAD BETTER PIC WHEN GET A CHANCE)
The end of this wire will be routed to the engine compartment fuse box. I melted a small hole the size of the wire to fit snugly by heating up a nail held with pliers. I made sure the entrance of the wire inside the fuse box was appropriate to the routing inside and no relays would get in the way.
I used the micro add-a-circuit that I purchased in this kit. I installed connectors on the wire inside the fuse box so that the wire could disconnected and the cover be lifted easily out of the way for access. The add-a-circuit is added to the 32 fuse spot/left high beam. The factory fuse was placed in the bottom space of the add-a-circuit and a 2 amp fuse was added to the top fuse space for the trigger wire protection. This and the other fuse tap that will be used are installed in the correct orientation for the incoming and outgoing voltage. Hence there is a right and wrong way, but the easiest way for this application happens to be the most convenient. Installing the wrong way will be difficult because the add-a-circuit pigtail will hit the side if the fuse box. Place the micro add-a-circuit firmly into position 32 (left high beam).
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