How-to: Install auxillary reverse lights **UPDATED WITH SWITCH**

[tast101]

From TF.Com

After getting my windows tinted, I realized that it was EXTREMELY difficult to see out my back window at night (street isn't lit well... the lights reflect off the wall and make it hard to see). I looked for solutions, but couldn't find anything that really fit. I saw that you can just throw in a 55w light bulb in the stock location, but it didn't help much and was reported to burn / melt the plastic lens after time. There was a kit made by White Night that gave me an idea.... here's a picture:

They wanted $99 for the kit plus some extra wiring harnesses and adapter brackets to make it all work without extra wiring. I could not afford it, but I could pick up some driving lights and do it myself.

I started with Pilot HID-simulated driving lights (in other words: cheap fog lights... anything with 55w dual lights will do) for $19.99. Here's a picture:

...and a link

These lights came with the wiring, mounting hardware, and a switch(which I'm not going to use). You will need a few connectors:
Tap splice:

Disconnects: (optional... if you want to be able to disconnect the lights in the future)



OR... if you can just get this:


and use a male disconnect, it is much easier. Otherwise, you will have to create your own disconnect on the splice. Again, the disconnect is optional. you can simply use the tap splice to permanantly splice the wires, if that's what you prefer. I knew I wanted to wire in a switch at a later time and would need the disconnect, so I used it. For sake of this how-to, I will use the disconnect that I used.

Once you have the parts, you will need to find the light green wire that comes out of the factory trailering harness. (should be the one to the middle pins of the harness). For safety sake, test the wire with a continuity tester or a multimeter to make sure you've got the right one. I turned the key to "on", put on the parking brake, and shifted to reverse to test this. ***USE EXTREME CAUTION - THE VEHCILE CAN ROLL OVER YOU IF YOU DO NOT USE THE PARKING BRAKE OR A WHEEL STOP***
After you test the wire to make sure you got the right one, place the open end of the tap splice onto the wire. Stick an un-stripped wire into the closed side (there is a barrier in the middle, so make sure your wire goes through on the right side, or you will not splice the wire correctly) When both wires are in, use pliars to crimp down the metal connector and secure the connector strap across the connector. Strip the other end of the wire you spliced into it and place a female disconnect onto it, and crimp it. This will give you a spliced disconnect. Tuck the new connection back into the wire loom and tape it up with electrical tape to make sure it's secure and safe from the elements. (leave the disconnect hanging out).

Now, it's time to find a ground. There are a few places to find a ground, but I was uncomfortable with using the grounding strap for the fuel filler neck, so I created my own. Using a self-tapping screw (or drill a hole, and use a fine-threaded sheet metal screw) you can attach a new ground to the chassis. I did mine on the driver's side, right behind the bumper / hitch mount. Attach the black wire on the light harness (from the Autozone kit) to your ground. The kit has a small open-end connector on it that can be easily attached to a ground.

At this point, you can add a male connector to the white wire in the cabling kit and plug it into the disconnect if you want, however I would wait until the lights are mounted before connecting power to them.

I chose a spot in the bumper (between two long holes) to mount my lights. I also wanted to aim them a little to the sides to get a better viewing angle. This is not required, however if you do, you will get a better angle. The supplied screws are not meant to mount to metal, so I would not recommend using them. Use a sheet metal screw (3/16 is a good size) that is fine or standard threaded (DO NOT USE COURSE THREADS AS IT WILL NOT SECURE CORRECTLY). Drill your pilot holes (if you're using 3/16 thread screws, I would use 5/32 pilot holes as the bumper is rather thick and WILL bind a screw if the hole is too tight. Mount the lights using the supplied brackets and bolts / lock washers and finger tighten. (I used the middle hole as it let me adjust the lights better) Connect the supplied wiring from the lights to the correct color-matched connectors. If you have not added your male end to the white wire, do so now and plug it into your connector. Test the lights by using the method stated above for turning on your reverse lights. The lights should come on with your reverse lights. If they do not, check fuses, and make sure you have all wires secured and matched up correctly. If they turn on, you're done. You can either tuck the wires up into the bumper and secure them to the wirelooms that go across the back, or if you're like me and wanted the "stock" look, you can buy 10 feet of 3/8" wire loom for about $.99 at a hardware store (read: Home Depot) and make it clean. I zip-tied all the extra wiring together and placed it into the loom, then zip-tied the loom out of the way.

When you're done, your Tahoe should look like this:

And the people seeing you back up will see this:


For a mere $25-30, you can have as bright of lights as the $99+ systems, and it doesn't require relocating the trailer wiring harness.

If you're good with electrical, you can also wire in a 3-way switch that will allow you to turn them off, turn them on by reverse, and turn them on for utility. That will be my next step.

 

[tast101]

Pt 2

Got the switch in today. It was a bit tougher than I had originally planned, but I really like the functionality! SO... here goes...

What you'll need:


Pictured:
3/8" x 10 Wireloom
16ga wire x 25ft (green)
16ga wire x 25ft (red)
3 x 18-14ga disconnects (female)
1 x 18-14ga disconnect (male)
1 x 18-14ga tap splice
1 x On-Off-On switch (rated at least 20a@12v)
1 x piece of cardboard
utility knife
Dremel w/ cut-off tool
Wire strippers / crimpers
Pliars

Not Pictured (because I figured it out later...)
Drill
1/2" drill bit
electrical tape



Here's the switch I ended up buying. It's hard to find a good On-Off-On rocker switch for 12v DC applications. I ended up getting this AC application, but the rating is right, I just didn't use 3 of the terminals.



I looked for the PERFECT spot to put the switch, but couldn't find it... I thought here would be a good place:


... but realized that it just felt out of place and that the rear A/C unit was placed in that area.

Then, as I was looking around near the fake speaker area... I found the perfect spot... the pillar! There was a hole and everything. Ok, now for the wiring....

There was no magic hole I could go through to get to the outside, so I found I would have to make my own. I took out the taillights using these screws:


... and found the perfect place:


As the picture shows, I wrapped my wires in the loom and stuffed it through the 1/2" hole I drilled out behind the light. I found that wrapping your wires in the loom first was the easiest way to go. I also had to drill out the 1/2" hole and slide the loom through on the other side to be able to get my 12v power source.


Now that I have my holes drilled, here's the wiring:


Green 16ga wire is connected to the disconnect I made in the trailer wiring. (see post above about light green wire... see the connection?) Since that was a female disconnect, I added the male disconnect to the end, and tied it in. The red goes straight to the 12v power source. I decided to use the 12v cigarette lighter as a source as it will be rarely used and is 20a fused.


Just tap splice your red wire into the orange wire that goes into the lighter, and you will have a good fused 12v source. The white wire is from the light system that I originally plugged into my spliced disconnect at the trailer wiring harness. It was JUST long enough to reach my location. Once the wiring was in place, I plugged my switch in like this:


This switch is meant to work two devices from one source instead of control one device with two sources, it just required reversal of the wiring. The center pin needs to be your device wire (the white one that goes to the lights), then plug the other two into the opposite ends. When the switch is in the middle position, it will disconnect all circuits. When it is in the up position (the red wire) it will turn the lights on with the 12v source. When it is in the down position (the green wire) it will only turn on when power is applied to the reverse lights. I test cut my switch hole in the cardboard, and once it was correct, I transferred it to my plastic panel via utility knife. I then used my dremel to cut it out. Here is the final result:


Unfortunately, my wife, child, and dog were all running around in the garage, and I was distracted... it came out a LITTLE crooked, but it works!

So, in the down position... I get:


In the middle position... I get:


In the up position... I get:


It took me about 2-2.5 hours with some interruptions and plan changes. Now, I can use my lights without having to have reverse on!

 

[Stik]

nice post Tast101...one more mod to add to the ever growing list....

 

[2000Yukon]

Thanks for the write up. Need to get this done along with many other things.

 

[kickitandholdit]

thanks looks handy

 

[borohoe]

Thanks for the tutorial. I just got done doing this, and it looks great (minus the three way switch because I ran out of time...gonna do this tomorrow).

Regarding the ground/black wire from the lights...I just grounded them the the lighting bracket itself, as it was all metal and I drilled clean holes to mount...works out great.

Also, Radio Shack still has a surprisingly large amount of electronic components in their store - here I found the splice/disconnect for the trailer hitch wire, as well as the switch.

Can't wait to get the switch installed and turn this into a full utility project. Thanks again!

 

[withac]

I'm getting ready to do this and I plan on mounting the switch on the dash. Rather than run the red and green wire all the way up front from the back wouldn't it make more sense/what would be wrong with splicing into the green trailer harness wire right under the dash for the reverse controlled setting and the then splice into the cigarette lighter wire for the red constant power setting, then you would only have to run one wire to the back for the lights.

 

[withac]

bump

 

[withac]

I couldn't find a switch rated at 20 amps but found a 16 amp switch, do you think I'll be okay?

 

[withac]

Okay, here’s my experience. I mounted the lights under the bumper like instructed then used wire loom and zip ties to secure it and route it up through to where the tail light is. I then drilled a hole in the side (hole placement is critical or you could end up drilling into an empty cavity) and used a grommet in the hole so the wires wouldn’t rub on the sharp metal. Then I pulled the wire through to where the factory sub is mounted. From there it was easy to run the wires up to the front tucking them under the trim or popping off the thresholds to run the wire under them. I thought I would just find a 12 V lead and the back-up light wire up front rather than run them all the way from the back. I found one 12V hot and spliced into it but got nervous because I didn’t know what it was from so I undid the splice and just spliced off the hot wire coming directly from the battery to the relay (I’ll get to that in a minute). I spent half the afternoon trying to find a back-up light wire under the dash and finally gave up. I’m sure someone else could have in ten minutes but I bagged it and went to the back end, spliced into the wire from the trailer wires, and ran it up to the front next to the wire for the fogs. My plan was to use two indicator lights for each position of the rocker. Once again, I’m sure someone else would figure this out sooner but I didn’t. With the lead for the indicator light coming off the power wires going into the switch the constant power indicator light was always on. The way to wire it is to splice off the wire coming out of the switch to the fogs and use that for the indicator light. Of course that way it lights up under constant power or when the back-up lights come on, but that’s okay, if the light is on and you aren’t backing up you know the switch is flipped the other way. So, I could have gotten by with one indicator light but I’d already mounted two so the second is non functional. Finally, as suggested by others, I used a relay so it would be carrying the load not the switch. I wired it like the diagram except it was a three way switch so there are two power sources coming in.
Did any of that make sense?