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Adding reverse lights

firemanjay

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Have searched but to no avail, what i am needing assistance with is I would like to install reverse lights to brighten up the rear, would like them to activate when i put the truck in reverse (would tap into the trailer harness reverse circuit) but would also like to have a switch in the cab that will activate lights separately when not in reverse. I don't know how to wire a relay to accomplish this set up. Any help would be greatly appreciated
Thanks
 

Mjgain

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Use a relay. Run the reverse light trigger wire and your switch out put wire to pin 86.

autorelayschematic.jpg
 

Richard320

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I was thinking this. When nothing is happening, the auxilliary backup is fed by the trailer BU. When you flip the switch, it breaks that feed and powers it from the trailer charging line. So you need a fuse tap and a switch and then a single strand of wire from the switch to the relay. I'd mount the relay somewhere behind the tail light or under the bumper where it's close to everything.

Edit: I might have 85 & 86 backwards
 

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Mjgain

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Both triggers to pin 86?
Yes. No special switch, but need an ignition switched 12v source as the trigger. Recommend fuse 66 under the driver side dash
 

Mjgain

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I was thinking this. When nothing is happening, the auxilliary backup is fed by the trailer BU. When you flip the switch, it breaks that feed and powers it from the trailer charging line. So you need a fuse tap and a switch and then a single strand of wire from the switch to the relay. I'd mount the relay somewhere behind the tail light or under the bumper where it's close to everything.

Edit: I might have 85 & 86 backwards

I would recommend running the relay under the hood. That way, if you add any other lights and power off something like the trigger 4, the wires are already there.

Definitely use the 7-pin BU (center pin) as the trigger for the relay.

I basically ran light power, light ground, and BU trigger into the engine bay. I followed the power wire for my front camera install to run the switch wires into the cab.
 

Richard320

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I would recommend running the relay under the hood. That way, if you add any other lights and power off something like the trigger 4, the wires are already there.

Definitely use the 7-pin BU (center pin) as the trigger for the relay.

I basically ran light power, light ground, and BU trigger into the engine bay. I followed the power wire for my front camera install to run the switch wires into the cab.
I think that would overly complicate things, especially since he also wants it to come on automatically with the backups. There won' be any lights on the front that tee into the reverse lights. Wired with the relay at the rear, a single really thin wire is all that needs to run the length of the truck.

And I just remembered this. No wires to run, just tap into the 7 way and then match the fob to a homelink button on the visor. https://5thgenrams.com/community/th...rs-diy-how-to-for-under-20.34811/#post-499994
 

Mjgain

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I think that would overly complicate things, especially since he also wants it to come on automatically with the backups. There won' be any lights on the front that tee into the reverse lights. Wired with the relay at the rear, a single really thin wire is all that needs to run the length of the truck.

And I just remembered this. No wires to run, just tap into the 7 way and then match the fob to a homelink button on the visor. https://5thgenrams.com/community/th...rs-diy-how-to-for-under-20.34811/#post-499994

It adds some initial complexity, but well worth it. I have mine set up exactly how he wants it: comes on automatically with reverse lights (triggered by BU trigger from 7-pin) and I can turn them on with my in-cab switch.

You're right though. Run one wire the length of the truck (relay in rear), run two (relay in engine bay and lights grounded to chassis, or run three (relay in engine bay and lights grounded to battery).

Results will be the same.

The wireless controller is tempting for one input. OP, if you have no plans to run any additionally lighting, this may be the best recommendation
 

Jako

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I wired my reverse auxiliary lights with a Double Pole Double Throw (DPDT) switch along with a set of lights at the tailgate. I leave the switch so the auxiliary reverse lights come on when in reverse. The switch allows me to turn on the reverse lights along with the set at the tailgate. Works great when the sun goes down and not finished with a "job". Wish I had it back in the Boy Scouts of America days. Middle position turns the power off all together. You can tap into the trailer harness wires or use a Curt 56070 and attach the appropriate wires.
Best of luck on your project.
 
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firemanjay

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It adds some initial complexity, but well worth it. I have mine set up exactly how he wants it: comes on automatically with reverse lights (triggered by BU trigger from 7-pin) and I can turn them on with my in-cab switch.

You're right though. Run one wire the length of the truck (relay in rear), run two (relay in engine bay and lights grounded to chassis, or run three (relay in engine bay and lights grounded to battery).

Results will be the same.

The wireless controller is tempting for one input. OP, if you have no plans to run any additionally lighting, this may be the best recommendation
That sounds like a good idea with the homelink, but may do more lights later so a basic relay setup will probably work best now to decide on a switch and location
 

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