Wiring Backup Lights, control circuit(s)

StG58

StG58

TJ Guru
Supporting Member
Joined
Oct 29, 2015
Messages
6,666
Location
Orygun, the wet side...
I"m looking to put a much brighter auxiliary backup light on my TJ. The intent is that when the rig is put in reverse, the auxiliary backup lights come on. That's the simple part. It would also be handy to be able to turn the lights on for use as work lights independent of the backup circuit. Additionally, it would be nice to be able to turn them off around town so other drivers aren't blinded in parking lots and such.

I saw a wiring diagram once that allowed for this, but can't seem to locate it again.

So, here's what I'm looking for:
1) Auxiliary backup lights on when in reverse.
2) Auxiliary backup lights off when in reverse.
3) Auxiliary backup lights on with dash switch for use as work lights.

I'm electrically ignorant, so help would be greatly appreciated. Thanks!
 
That's what I have done on my WJ, and will be doing it on my TJ also. I used a SPDT switch with a relay. I tapped into the reverse lights, and ran a wire to one pole on the switch, and ran another wire with constant power to the other pole. With the relay wired up (ground, power, wires to lights) run a wire from the middle connector of the switch to the relay.

SPDT.gif




attachment.php?attachmentid=596223&d=1423576028.jpg
 
  • Like
Reactions: RipSteakface, DickD1911, BigskyTJ and 3 others
No problem!! I forgot to say to ignore the wire colours listed for the light though, as this was just a pic I pulled from the web, and I'm not sure what colour the wire is on a TJ.
 
  • Like
Reactions: Chris
Having done this, you can do it without the relay in the above drawing if the aux backup light is an LED. That is because LED lights don't draw enough current to be a problem for the reverse light circuit. The relay would only be required if you went with a standard incandescent back up light which draws enough extra current to require the relay.

My TJ used to use an incandescent aux reverse light I controlled via a relay like shown above. Once I converted to an LED light, I was able to get rid of the relay and simplify the wiring. I use a SPDT (single-pole double-throw) switch (like shown above) with a center-off position.

The switch's center connector connects to the LED light, one of the outside connectors goes to the reverse light wire, the other outside switch connector connects to a constant source of 12 volts. So in the switch's center position, the aux reverse light is off. Throwing the switch in one direction causes the LED light to illuminate when I shift into Reverse. Throwing the switch to the other position turns the LED light on without needing to shift into Reverse.
 
Last edited:
  • Like
Reactions: derekmac, lowranger, StG58 and 2 others
I cut my lenses and installed a set of 35 watt Halogen aux lights. These lights have been lying around for years so I thought I would put them to good use.The back of the lights without the case fit perfectly. I tied the wiring into the original circuit and have had zero issues. Bright as hell to boot.

DSC07585.JPG
 
  • Like
Reactions: JMT and Sasquatchewan
That is true Jerry, but I personally don't trust factory wiring to handle much more than the stock bulbs. I know they will handle some, but I prefer the peace of mind of using a relay.

I believe my two 4" LED lights are 18 watts each, and the halogen I had before them were 55.
 
  • Like
Reactions: Stinger
Bringing an old thread back from the dead here. Finally getting around actually putting a pair of led flood lights into the back bumper for auxiliary backup / work lights. Anyone have a hot tip for a good place to tap into the reverse light circuit?
 
StG58 said:
Bringing an old thread back from the dead here. Finally getting around actually putting a pair of led flood lights into the back bumper for auxiliary backup / work lights. Anyone have a hot tip for a good place to tap into the reverse light circuit?
Click to expand...

Your tail lights are only held on by 3 screws I believe, well after the 4 holding the lens on, and you can tap in right behind the tail lights, as you would if you were wiring trailer lights I am assuming.

I would tap in somewhere between the bulb and the plug so you are not tapping into the main wire harness. Just so if anything goes wrong you are tapping into a small aux harness.

That only goes is if you do as Jerry mentioned earlier if you are using a LED backup lights.
 
  • Like
Reactions: StG58
That's a lot of wire to go from there to a dash switch and back to the auxiliary lights. I was kind of hoping for someplace closer to the dash.
 
I taped into the backup circuit in the wiring loom just below the drivers door when I hooked up a backup camera. It was easy to figure out which wire I needed by looking inside the tail light at the wire color going to the backup bulb.
 
  • Like
Reactions: StG58
DickD1911 said:
I taped into the backup circuit in the wiring loom just below the drivers door when I hooked up a backup camera. It was easy to figure out which wire I needed by looking inside the tail light at the wire color going to the backup bulb.
Click to expand...
Outstanding! I'll start there.
 
Top Bottom
Back