Backup/Floodlight question

Hi again.
I'd like to install 2 floodlights on the top, rear of my trailer. I'd like them to serve a dual act as backup lights when the tow vehicle is put in reverse and to act as floodlights when I need them. I am thinking it is as simple as hooking a 3 way switch into the circuit with one pole to the yellow wire (backup on the trailer wiring harness) and the other pole to the trailer battery. Am I on the right track? Also, is there any danger of screwing something up if the switch is in the wrong position, as in shifting to reverse while the floodlights are running from the trailer battery?
Thanks again for any and all help.


Senior Member
Re: Backup/Floodlight question

Probably not (on the right track). 'Floodlights' generally will pull a lot more current than a standard 'backup' light and I have heard of cases where 'too much' trailer light draw has caused problems with the circuitry in the tow vehicle. I believe they have devices designed to protect against this. You will always want the flood lights powered from the trailer battery/converter and never drawing significant power from the tow vehicle.

What you will probably want to do is have your manual flood light switch 'in parallel' with an electronic switch controlled by the backup wire. This way either one or both can cause the lights to come on, and the 2 circuits are isolated from each other. If you can't find a device ready made to do this, perhaps a relay closed by the backup signal would be the easiest and most reliable 'electronic switch'. A cleaner, but more complicated setup would be to have the 'electronic switch' controlled by an 'OR' circuit fed by a switch (for manual) and the backup signal.

In any case, consider having a '3 position' control switch, for completely off, under the control of the backup signal or manual on.
Re: Backup/Floodlight question

Aw take all the fun out of modifications.....doing it your way would eliminate the possibility of ever being able to amaze your fellow campers with your talents... Just imagine how it would feel to have your camping neighbors watch you back in with those flood lights blazing.... the after you've parked it, they would be even further flabbergasted when you lit up the back of your site....
I can just see them now saying " Ur-a, ur-a ur-a, are those your lights??"
Re: Backup/Floodlight question

Now don't misunderstand me by what I say! I'm all for it, but I'd do it with an RF link into the truck cab and have motorized floods so I could shine 'em all around and blink them and change the colors and ... !

woodworker1, I don't mean no disrespect. I'm just havin' fun. I know you're doing a wiring job and only want to do it right. I think you need a relay interfacing those 'floods', too. You've got plenty of battery power in your trailer.


New Member
Re: Backup/Floodlight question

I mounted backup lites on my 5ver on the spring hanger brackets to the inside of them. Put a switch inside a compartment door where it was easy to get to and to the battery. With them down low they really showed up the ground where the wheels were going to be and made the whole back half of the unit visible with out the clutter look of hanging them on the back. Never fails to work later on Fridays and never got to set up in the daylight; Murphy's Law.
RE: Backup/Floodlight question

Thanks again for the replies. I think I may have solved my dilema. I found a remote switch that will handle 15 amps. It's good for 75 feet and comes with 2 fobs. Can be wired along with a switch so either the remote or the switch can be used. Only $39 American, so this is probably how I will go.
Should be handy backing this thing up when it's dark.
The link is here if anyone else is interested.