TruckHacks - Reverse Lighting

Looking at my rear window, you'll notice that's some pretty dark tint. It's great for privacy, but a bit of a killer because of the size of my truck. The dark tint makes it pretty tough at night in tight spaces and worrying about backing over someone walking in a parking lot due to limited visibility.

I was looking around Checker Auto Parts while waiting for my wife's eye exam to get done when I saw a pair of 55w halogen "fog lights" with a nice low profile for about $25.00. I've seen other trucks where they've mounted similar lights in the back for the purposes of either backing up, or just lighting up the area behind the truck for loading. I thought I'd give it a shot and see how well they did.

I wanted to install one of the lights so that it came on when I put the truck in reverse rather than a separate switch to turn the light on. Later, when I get my light bar, I'll have a couple of lights facing backwards to light up workspace behind the truck, so I wasn't really looking to be able to turn this light on for any other reason.

After looking at the wiring harness schematics for both the four wire towing and seven wire towing connectors (I have both installed) I realized it wasn't going to be as simple as splicing into one of those. Nope... I was going to have to splice into the actual reverse bulb wiring. Yuck. UPDATE: The wiring diagram I had for the seven pin trailer harness wasn't very good. I've since learned that the center pin (#7) is the reverse wire. Life would have been much simpler had I known that earlier.

I removed the rear driver's tailight and started testing for voltages. This was made a little more interesting because my wife was at the gym, so I set the emergency brake, left the driver's door open, chocked the tires, put it in reverse (engine off) and stood off to the side of the truck to test for which hot wire I needed to splice into. I decided to ground the other wire directly to the chassis rather than splice into a ground wire on the tailight for the sake of a cleaner and easier install.

Above are pics of the fog lights and my kit of connectors that made this a nice professional looking job. I took these after I'd already installed one of the lights, but it did come with two lights and the associated hardware.

I looked and looked for a good place to mount the light that would make it more or less hidden but still have a good view of the area for throwing the light. I finally decided to mount it under the class IV hitch and since the kit came with double sided 3M tape I thought I'd give that a shot first for a couple reasons. The first was that I like the non-permanent option in case I change my mind about the location in the next few days, and the second was that I wouldn't need to weld the bracket to my hitch. If it turns out the double-sided tape isn't working, I'll do a couple to three tac welds with my mig.

Here's how it looks mounted and the wiring I ran. Left column, second row you can see where I ran the wiring to splice into the tailight.

After a few weeks with the reverse light installed, all I can say is that while it helped, it didn't make a whole lot of difference. I plan of doing this again with my Power Wagon, which doesn't have back window tinting and will be wired into the #7 pin of the trailer wiring harness. I'll let you know how that turns out.