Switch at Tailgate for Cargo Light

FlBowhunter · July 14, 2014

Hi Guys,

1st time poster, been lurking around for awhile but never had anything useful to contribute.

Not sure how useful this is or if it may have already been done but if not here goes.

Well I really hated the way you have to go in the cab to turn on your cargo light in the back and after a little research I was able to come up with a really simple inexpensive way to add a switch for the cargo light in your truck bed.

Cargo Light Switch.pdf

When I took my multi function switch apart I realized it was only a momentary switch that sends a ground signal to the BCM to turn the lights on and off. I then was able to find the correct wires to tap thanks to the gmuppfitter site. I prefabbed the switch with about a 15' wiring harness (26 gauge wire was all I used) and encased it in a small 1/4" wire loon. Then I popped out the plastic plug near the back f the bed on the drivers side and mounted switch in the plastic plug. I then pulled the wire thru the hole and popped the plastic plug back in place. Then I removed the left rear taillight and was able to reach over and grab the harness pull it back to the light and to tie it off to the existing wire harness. I did this all the way to the front of the truck. I came in to the cab thru the large grommet by the parking brake. ran it over to the BCM. Trimmed my wires and tapped the signal and ground wire for the cargo lights. Now I have a switch in the Pickup bed for less than $20 and a couple of hours of my Saturday.

The switch actually works like a 3 way as I can now turn it on in the back and then off in the front or vice versa. Because I am just sending the BCM a signal from another source the light retains all the original functions like the battery saver and it turns off when you put it in forward. I have a cover on my truck bed so I just used a Radio Shack switch but if you do not have a cover or cap you may want to use a Marine grade switch.

Cargo Light Switch.pdf

MNDaveC · July 14, 2014

Impressive! Great idea.

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rcmike · July 14, 2014

if you live anywhere near the d/fw area. ill pay you to do this mod on my truck ? if not ,that's cool. thanks for sharing the idea, sounds like a good one.

Newm · July 14, 2014

That is an awesome idea!

J-Jeezy · July 14, 2014

I wish there was a was to bypass the factory switch so it would have constant power and wouldn't turn off when gear is engaged

thewhitestallion · July 14, 2014

I wish there was a was to bypass the factory switch so it would have constant power and wouldn't turn off when gear is engaged

that's easy. just run a power and ground to a switch and put that switch wherever you want. now you would have 2 ways of turning on the bed lights.

J-Jeezy · July 14, 2014

I would like to retain the factory switch. Just have it function like a standard constant switch though that won't cut off

bdbake01 · July 17, 2014

it's possible that a maintained switch set up in this manner, i.e. holding a constant low/grnd on the BCM, would maintain them on indefinitely. Not sure, but it might.

FlBowhunter · July 17, 2014

it's possible that a maintained switch set up in this manner, i.e. holding a constant low/grnd on the BCM, would maintain them on indefinitely. Not sure, but it might.

I don't think that would work. If that was the case you could hold down the cargo lamp switch in the multi-function switch and the light would stay on all the time. You might be able to rewire the cargo light from accessory power with a On-Off switch using 2 relays that could trigger using the factory switch.

http://www.emil.matei.ro/onof2.php

Not sure it is worth that much effort, might be easier to just add a light with a separate switch.

bdbake01 · July 17, 2014

Well if you haven't tried holding it down for several minutes??? I'm guessing it won't, but it may.

Could do it with a single pole, double throw switch. Hot lead goes to lights, the switched leads go to BCM and an alternate 12v source. In position 1, factory. Position 2, hot all the time.

CoasterCOG · July 17, 2014

Great idea and nicely documented!

itsmerce · July 18, 2014

Can we get some pics!

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Crf450r420 · July 18, 2014

Now if we can just get someone to make it so you can hit both the lock and unlock on the remote to activate the cargo lights. I will do this mod ASAP. Thank you.

Crf450r420 · July 18, 2014

New idea. I wonder if we can make it where the mirrors hit a momentary switch when they swing in. Then you could fold the mirrors with the remote to activate the cargo light. Just a thought.