Backup floods with optional switch?

Stole the image below from the illuminated ignition switch thread. I want to try wiring up a pair of LED fogs under the rear bumper so that they can be triggered by either the reverse lights or a dash switch. Is this even an apples to apples setup? What would need to be modified in this diagram to make that work? I know the concept is the same (or I think it should be) I just can't sort out what to connect where.

@Up2NoGood

 

I remember looking into doing this and ended up deciding to just do it directly to the reverse lights. If that ever becomes an issue for inspection I will just wire them to a switch instead. I remember it needed like multiple relays and just more wiring than i wanted to deal with.

 

I wouldn't use that diagram since it's intended purpose is for something else completely. What you would need are 2 separate relays:
the first connected to your hot lead going to the reverse lights which would then trigger the LEDs when the truck is put into reverse (the easiest way to wire this circuit without running a mess of wires to the batter or cab). A second would be run like your typical harness with the switch. Hooking both up to your +/- at the main leads for the lights would be the easiest way so both circuits don't interfere with eachother.

 

Couldn't it be done with a single relay and a SPDT switch? Connect the lights to battery/ACC/IGN in series with a fuse and N.O. relay, then send the activation wire from the relay to the SPDT switch, which you can then wire one throw to battery/ACC/IGN and the other throw to the reverse lights hot-when-in-reverse? Would this not give you three choices for your supplemental reverse lights, "OFF, "ON", and "AUTO ON WHEN IN REVERSE"? I'm having trouble envisioning if this would screw anything up. I've had more experiences with electronics in my life than I care to admit where I thought I had it perfect then I hit the brakes and the trunk pops.

 

That would actually be a neater way of putting it together. It might get tricky when it comes to switch illumination, if OP desired, but a neater package for sure.

 

Any chance you could diagram that real quickly? I think I know what you're describing but want to make sure.

 

If i am not mistaken it may have been @Bruce988jl that had a diagram, it was a long time ago and I have no recall as to what it entirely entailed.

 

here are some possibly helpful links
https://www.tacomaworld.com/threads...ghts-to-switch-and-preexisting-lights.266006/

https://wayalife.com/showthread.php...ith-reverse-and-switch-for-turning-on-anytime

 

Found this one, I think this is what you're talking about, right?

 

OP I'm not an electrician or any kind of expert just a weekend warrior but this is what I was envisioning, I just jotted down what was in my head. It appears to match exactly with what you just posted. You can wire the "ON" feature to the battery if you want it to work without the key, or ACC/IGN if you want to have to put the key in the use it (I'd recommend this so you're less likely to forget and drain your battery).

 

Hm - I don't recall making a diagram for this however my electrical knowledge is limited - I'm just good at the wiring part thanks to my career path.

For my truck I have 12V power/GND run via 6awg cables under the truck to the bed for a bluesea fuse panel. I would tap fused power from that and then use a source from the reverse lights and the switch. I personally would never do this - I prefer everything to be controlled solely by a switch - having the ability to not have to worry when other people drive my truck and the led's coming on without warning isn't something I prefer. Regardless I'll give my 2-cents

I would use two SPDT relays - one to determine whether or not you're controlling the system from the reverse lights (defaulted) or the switched input and the other to provide an independent power feed to the led's. I only suggest the second relay because it'll give the LED's independent power - which isn't necessary however I'm picky like that.

NOTE - Disregard the labels on the bottom of the images below - I just pulled the image off the internet for the sake of time.

Control Relay #1 that determines the difference in input - Reverse Engagement or the Switched input
Pin 30 - Output to Source on Relay 2
Pin 85 - GND
Pin 86 - 12v Power from the switch
Pin 87 - 12v Power from the switch (basically tied to wire going to pin 86)
Pin 87A - Power line coming from the factory reverse lights



Control Relay #2 this activates the rear facing LED lights
Pin 30 - Goes to LED as Power
Pin 87 - 12V constant power (in this case my fuse panel or your battery)
Pin 86 - Comes from Pin 30 Relay #1
Pin 85 - GND
Pin 87A - Unused




Pretty much when you turn on your reverse lights it will always activate the LED's - however if say you're parked you can now activate the LED's via the switch. You can tie the switch into ign or acc if you want but I have all my switches fed directly into a fuse panel under the hood that has a constant on.

Now keep in mind my electrical knowledge is limited so this could be wrong however it makes sense in my mechanical engineering mind....

 

Hey people, just wanna let you know, don't pull more than about 15 watts off your stock reverse light wiring , it will cause the ECU to switch off your airbags.

 

This is what I did. Pulled from the reverse light and its so nice to not have to deal with a switch. Also nice to not have to worry about the lights getting ripped off on the trail. Its the yellow wire.

 

I was thinking about this route too, then over the weekend, someone mentioned to me that it would be useful to have them on a switch to use as work lights. I'm not sold either way yet but I'm leaning toward the switch.

 

I just did both. The bottom are switched, I can have them whenever. The small light on the roll bar is the actual reverse light.


I am so glad I have some on a switch. Its very helpful when doing a recovery or workin on stuff at night on the trail. Just back up to it, switch lights on, and you have a lighted work bench.

 

There's also times in the city when trying to park or whatever when I'd prefer not to blind the people in the lane behind me.

 

I installed a set of Bully hitch mount auxiliary backup lights. As long as you have a hitch on the back it’s easy. 1 wire to a hot lead or battery, one to ground and one to your back up light wire. There is a switch on the back of the light itself. Position 1 it operates when you shift into reverse. Position 2 is manual on for when you are stationary and want to light up the area behind the truck. Position 3 is off. Doesn’t come on even when in reverse. I leave it so it comes on every time I put it in reverse. The on position has come in handy for early morning fishing and hunting when I need light while gearing up.