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Discussion Starter · #1 ·
This is my first post here and I am hopeful you guys can help me out... I am looking to wire some reverse lights under my rear bumper for plowing but I don't want to leave the on year round so I was planing on using the 7pin trailer connection to wire them. My question is how do I go about this and what do I need like in line fuses or anything? I am using basic Hella Work halogen work lights they are ten dollars on amazon and they will work for what I am looking for. Any help you guys can give me would be great! Thanks!
 

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Good idea but you have options. Do you want to have the lights comming on and off as you shift or do you want them to have a toggle so you have light back there all the time?

I have under rail lights hooked up through the accessory wire that may or may not be connected (mine was tapped up under the hood) and i put a switch in the bed that i can use to see stuff that rolled around under my cover. The other wire is pin A wire color is 1 L-GN. That will come on and off with your reverse lights which may or may not be good for your needs and def not good for your lights :)

http://www.gmupfitter.com/files/media/p ... 100813.pdf
 

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No, you can run a wire along the frame and pop in behind the fuse by your left foot, then put your switch probably in the panel near the blinker. Unfortunate they didn't give us any switch spots like the old trucks but you can fab up one that won't be noticed pretty easy.

Sent from AutoGuide.com Free App
 

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I'd put a simple relay on there too actually. But in my 04 tahoe that i used to have, i had the roof rack lights that i made for it wired to a switch, but they would also come on whenever i put it in reverse. I did that so that if i was loading/unloading my boat, or anything like that i could just hit a switch and light up the area without the reverse lights, but it was cool to walk into the parking lot at night and hit the unlock button on your fob to have those come on with all the other lights too. really, if you just wanted a switch, you just need to run 1 wire from the lights POS side to the cab, like he said above, along the frame would be the easiest. you can ground the lights in the back so you don't have to have two running up front. if you went without the relay and just wanted to have a fuse on it (which should be fine depending on how much power your lights are pulling) you would run it up front to the switch on one of the prongs, ground your switch, then run a power wire from your switch to the fuse box.. i would probably use an empty fuse spot in the cab with a jump fuse or whatever you call it on there. basically it looks like a wire that comes out of a fuse, so you use the actual fuse spot as well.

what i did was basically that, but i also hooked up a relay under the knee bolster. under there is a wire that is triggered when your truck goes into reverse. that would be your trigger wire on the relay, hook up a small wire to the one you ran to your lights, then power and ground. should be able to use the same ones you already hooked up too. I'm not sure as to which wire it is as i have had my truck for a total of about two months, i've been a tahoe guy all of my life and recently converted to the silverado, and love it by the way.

I just always liked having my wiring and everything inside the vehicle as much as possible that's why i did it this way. you could very easily have a few short wires from the lights to the trailer harness as well and leave it all back there. simple relay just like the one above accept the wires would all be hooked up to the appropriate ones on the trailer harness. But if you want a switch (which is very convenient if you are going to have the lights, might as well be able to turn them on when you want, not just in reverse), then you'll need the switch. but then again you can keep it in the back too. there are many many options and this probably sounds vague as can be. I'll have to find the "how to" link from the z71tahoesuburban website that explains the wiring for the roof rack lights, its a great diagram.
 

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Sippi is right, I used the ACC wire for LED's so a relay isnt needed. The other way to do that is to have the option of automatic and switched lights at the same time. You could do this by using two relays. Run ground to a switch in the dash and then run it to a relay, run 12 volts to that relay, run a signal wire off your reverse light, positive side, and use a relay to change it into a ground (reverse polarity relay wire) and connect that ground (output) to the same relay post that you hooked up your dash switch too. That way if you hit the switch in the cab the lights will be on all the time which would help for plowing and they would also turn on when you put the car in reverse. You wont cross or blow anything since your signals are all ground.

Let me know if you want me to sketch up a diagram and parts list. It sounds complicated but its really just simple logic gate.
 

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Discussion Starter · #7 ·
Thanks for the help guys I think for now I am going to just run a switch since I don't know to much about relays but if you could find that how to then maybe I could figure out so I could have them come on with the reverse lights as well!

dj if you could sketch up how to use the relays that would be great I'm pretty good with wiring but just have never used relays before and don't wanna screw anything up in my truck, thanks!
 

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Here is a link to relays that would work (you can get them at auto parts too)
http://www.ebay.com/itm/Waterproof-12V- ... 1c3432985d

Everything that I use relays for, pretty much got from here:

http://www.the12volt.com/relays/relays.asp

Relays seem complicated but soon as you understand that that 'click' 'click' is just the pin moving from 87a to 87 as the power moves through the coil all kinds of endless possibilities come to mind. I used one to delete my DRL on my truck and have one revers polarity and trigger another relay for the parking lights, almost identical to this application except i am tricking one of the relays under the hood and not one i added. Actually understanding Relays will help you diagnose your car more efficiently if you are ever on the road dead since you will know, ok, i have click in the fuse box when i do that so it must be between the fuse box and the whatever component im diagnosing. All those little grey and black boxes under your hood use the same pin layout that i showed in my diagram.

Here are some diagrams

http://www.the12volt.com/relays/relaydiagrams.asp

you are using the Convert a Positive Output to a Negative Output diagram in my sketch.
 

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Here is the wiring diagram i used to hook up my roof rack lights in my tahoe. It shows how to do it with a switch AND to come on when in reverse together. just like i had mine set up. Like i said i could hit the unlock button on my fob and they would light up, basically anytime your normal reverse lights are lit up. But if i had it in park(or drive or whatever) you could hit the switch. Its a simple diagram so your placement of the switch, and finding the reverse wire is something you'd have to do as i haven't gotten there yet with the Silverado, but it will soon i'm sure.

By the way don't worry about the red line on the diagram. I cut it off because its for wiring them up to a back up camera which isn't applicable here.
 

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Sippi - Nice looking diagram but im concerned that since you have two + going to the lights from two sperate circuits that you will blow a fuse if you turn your lights on manually and then put the car in reverse. I allways try to wire my circuits so that the light allways sees the same + regardless of how many switches are depressed. Have you tried both at the same time?

My diagram is kind of spread out but if you tape two relays together you can do all your wiring behind one of your tail lights nice and tight, wire tie it up high so it wont get as dirty or wet and drop your wires along the same loom the factory uses. Nice clean install. Sometimes i use hot glue on the connections after i make sure it works to add a little protection that you can easily pull off later.

Let us know how it works.
 

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I guess you should prob put the switch on the ground side, i never thought about it. I got this diagram from a different forum and wired my lights up to it just like this. Had them on there for several years without any issues and even remember having them on with the switch several times and putting it in reverse to back up closer to a trailer or skinning rack or something like that. Maybe they werent drawing a lot of power or something i have no idea, but i never blew a fuse with it. But to be on the safe side, yea i'd add the switch to the ground side instead.
 

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Hey DJ, what if he did this...

Get a SPDT switch. The switch has 3 positions, On-Off-On, and 3 pins. The relay for the lights connects to the center pin of the switch, a constant "hot" source connects to one of the side pins, and the other pin gets the "reverse" signal from the backup lights. This should give you a switch with 3 modes (Auto-Off-Manual On) and the switch will then handle turning on the relay.
 

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It would work. But you would need to either find a signal wire under the hood for the reverse lights or run an additional wire from the back to the dash on top of the power running all the way back to the reverse lights. I really try to minimize putting power to an additional switch in my dash for fire hazard reasons. All the facotry switches are just ground signal wires that operate fly-by-wire relays because in the event of an accident 95% of your electricity is located outside the cab. On these trucks the ignition switch doesnt even run to the key anymore. When i installed my remote start i was astonished to find the wires to start your car are these dainty little signal wires and i had to solder on 14 guage wires to each one to trip the 'signal'

A really stealth way to do a switch that would be factory looking would be to use a factory fog switch (if you dont have fogs) and use the fog circuit with your run. Another way that is a little more complicated, but necessary if you have fogs allready, would be to take an acadia switch which looks identical except for the fog light switch is in the main circle and pull apart both switches and combine two fog light switches. That would take a little more finesse but there is a guy on here that did that in a sierra.
 
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