Aux Reverse Light wiring

[blacksheep37]

I'm considering putting in a pair of auxiliary reverse lights and have a wiring question.

I want them to obviously come on when I'm in reverse, but I also want to wire them to my switch to be able to turn them on any other time (think camping setup, etc.).

Do I really need a full wiring harness? Or can I just tap in to the reverse light wire that's on the 5pin plug? And then run a separate wire from my switch to power them whenever I want?

 

[John Jensen]

Yes and yes

 

[Richard320]

Check this thread. Added some reverse lights today

 

[blacksheep37]

Check this thread. Added some reverse lights today

I read through that thread the other day.

I was thinking I'd only use them as reverse lights, but using the harness allows them to have brake lights too. That's a little nicer

But as far as having a switch in the cab to turn on the reverse lights...would I just tap into the reverse wire on the 5 pin so when I hit the switch, the lights go on?

 

[Richard320]

I read through that thread the other day.

I was thinking I'd only use them as reverse lights, but using the harness allows them to have brake lights too. That's a little nicer

But as far as having a switch in the cab to turn on the reverse lights...would I just tap into the reverse wire on the 5 pin so when I hit the switch, the lights go on?

I don't understand the question.

 

[HSKR R/T]

If you want them wired in to the factory wiring harness for reverse lights, and have a separate switch to turn them on anytime you want you will need to either wire in two separate relays, or install a diode to protect the factory wiring from back feed when the switch is used

 

[blacksheep37]

If you want them wired in to the factory wiring harness for reverse lights, and have a separate switch to turn them on anytime you want you will need to either wire in two separate relays, or install a diode to protect the factory wiring from back feed when the switch is used

Thank you. Can you please pretend that I'm a complete idiot when it comes to wiring and explain how I would wire two separate relays? Or is it just one additional relay if I'm using a wiring harness?

 

[HSKR R/T]

Thank you. Can you please pretend that I'm a complete idiot when it comes to wiring and explain how I would wire two separate relays? Or is it just one additional relay if I'm using a wiring harness?

You want to use a relay for both options. That way when hit hit the switch, the power won't back feed into factory wiring because that relay is open. And vice versa. And if both relays are closed at same time, it's a wash and shouldn't hurt anything.

I would pull power from the 12v constant power wire in 7-pin trailer wiring harness. Use the switch to operate the relay. Same with the reverse lights. Use the reverse light power to trigger the relay. And you aren't risking back feeding any power into factory wires.

 

[John Jensen]

I installed rear auxiliary lights exactly like Blacksheep wants. Instead of a separate wire and switch to power them I used an Aux Switch power lead.
There is no need to add relays, etc. for basic LED pods and there is no back feeding

At rear bumper I:
Spliced a 14ga red wire to Aux Switch #4 power lead at rear bumper
Spliced a 14ga red wire to trailer connector "reverse" black wire
Spliced a 14ga red wire to each backup LED light, +side
Connected the ends of the four red wire ends

Spliced a 14ga black wire to each backup LED light, -side
Connected the two black wires to ground

Pretty basic

 

[HSKR R/T]

I installed rear auxiliary lights exactly like Blacksheep wants. Instead of a separate wire and switch to power them I used an Aux Switch power lead.
There is no need to add relays, etc. for basic LED pods and there is no back feeding

At rear bumper I:
Spliced a 14ga red wire to Aux Switch #4 power lead at rear bumper
Spliced a 14ga red wire to trailer connector "reverse" black wire
Spliced a 14ga red wire to each backup LED light, +side
Connected the ends of the four red wire ends

Spliced a 14ga black wire to each backup LED light, -side
Connected the two black wires to ground

Pretty basic

There is back feeding. You might not think there is, but there is. When you use the aux switch to turn on the LEDs, it's also connected to the reverse light wire and powers up that circuit.

 

[John Jensen]

There is back feeding. You might not think there is, but there is. When you use the aux switch to turn on the LEDs, it's also connected to the reverse light wire and powers up that circuit.

That reverse light circuit is closed until you go into reverse. How can there be a back feed? I've been wired like this since my 2020 was new. Same with my 2016 1500 ECo but used a separate switch (no Aux Switches)) and have had no problems.

If you are correct and there is a back feed it's inconsequential