Same lights for backup and flood?

[Dougeye]

For better visibility and safety at night, I'm going to add two LED flood lights to the top of the rear of our horse trailer, powered from the trailer battery and with a nearby switch. It would be nice if these lights also came on when backing up. So the lights would have to be wired to both the auxiliary and the backup circuits. So far so good, but I'm thinking I would want to add a couple of diodes, just before the wires from the two circuits come together. Would this work?

 

[Topzide]

Diode would be needed to keep from back feeding the reverse lights. You could wire switch from trailer battery then use a heavier diode current wise than light draw coming from reverse light trigger which I would use a relay. Of course, put a fuse in there just in case. Great project!

 

[i7win7]

How about a relay. Two wires from light, one goes to switch, other to relay. Wire from switch to +12. Wire from relay to +12
Then the other 2 relay wires are ground and backup light power.

Is the trailer battery used for emergency trailer brakes? Is so, maybe a larger battery. If not, wiring in parallel should allow tow vehicle to charge batteries.

 

[Dougeye]

How about a relay. Two wires from light, one goes to switch, other to relay. Wire from switch to +12. Wire from relay to +12
Then the other 2 relay wires are ground and backup light power.

Is the trailer battery used for emergency trailer brakes? Is so, maybe a larger battery. If not, wiring in parallel should allow tow vehicle to charge batteries.

Thanks, I'm liking this idea, but I can't figure out the specific wiring of the relay... could you explain it a bit more? Which side of the relay gets which wires?

As for the trailer battery, it's one of those little sealed units but I'll replace it with a deep cycle battery, and yes, with charging from the tow vehicle and a battery minder when it's parked.

 

[Al 2]

Not exactly what you were asking for but just a suggestion for others who may want to add another set of back up lights , side lights, flood lights or whatever on a separate switch. For $20 or so, you can buy a small remote unit that you control with a key fob. Just power this box from an existing power source, ie your tail light circuit, and use the fob. When I mount my extra back up lights I'm going to add a small LED light on my trailer facing forward to let me know when the back up lights are on.

Something like this.
Relay Switch DC 12V Wireless RF Remote Control Switch 433Mhz One 1-Channel with Two Transmitters: Amazon.ca: Tools & Home Improvement

Al

 

[Topzide]

Go to Car Alarm, Car Stereo, Mobile Video, and Cruise Control Info for Installers.
Great reference for wiring relays and the difference between different types.

 

[Diggin It]

Wire the lamps to the wiper of an SPDT relay. Wire a switch to the NC contact of the relay. Wire the backup light circuit to the coil and NO contact of the relay.


Normal Operation (NOT In reverse).

Relay de-energized. Switch turned on, power flows through switch and NC relay contact to lamp.


BackUp Operation (in Reverse)

Relay energized by the backup circuit, pulling the wiper to close the NO contact, allowing power to flow to the lamps.

 

[i7win7]

post 7 will not work for you, you want "extra" reverse lights - reason for relay. You want manual on/off control of "extra" lights.
hope this video and my comments help.

Relay Wiring Diagram - Bing video

terminal 86 is wired to backup light.
run extra wires from 30 and 87 for your toggle switch

 

[Diggin It]

post 7 will not work for you, you want "extra" reverse lights - reason for relay. You want manual on/off control of "extra" lights.

Which is what it provides.

 

[cmyoung2]

Might be easier just to add 4 lights, two for backup and 2 for work lights. They are not very expensive. Most don't realize that the purple wire in the truck wiring harness is for backup lights. Have them on my bigger trailers, wonderful at night.

 

[r porter]

personally i just walk back and turn them on and then back up. it only happens a half dozen times a year.

when i ordered the featherlite i had back up lights put on and then asked them to put them as high as they could. i promptly put them on a switch and presto saddle up lights and back up lights

 

[BoylermanCT]

I added 2 LED's facing forward and 3 LED's facing backwards to my tractor. My tractor's light switch on the dash had position 1 for low beams and when you moved to position 2, high beams came on while low beams stayed on. I unhooked the original headlights and wired the forward LED's to the low beam switch and the rear LED's to the high beam position.

 

[Xfaxman]

Over the years most of our horse trailers have had loading lights with a switch at the back. Turn it on if needed for a back up light.

 

[i7win7]

View attachment 663030

Your correct Diggin It, Saw two switches in series (meaning both must closed). Didn't realize 2 position relay, brain was only thing of single position relay.

 

[Birdhunter1]

When I rewired my horse trailer when I bought it I wired in to my reverse circuit a 4” diameter LED white light right below the tail/turn light on each side.
Having one up high might be handy but the ones I have mounted down low light up where the mirrors can see very well at night when backing up.

 

[Dougeye]

I appreciate all the help and suggestions... I'm good with a lot of automotive wiring stuff, but I can't quite sort out this particular scenario. If it was just me, I'd go with manually turning on the work light switch when backing up at night, but She Who Uses The Trailer The Most probably wouldn't like that on a dark and rainy night... so I've decided to install four lights instead of two, separating the backup and work light functions. The existing tail/brake/turn lights on the trailer are the 6" surface mount oval type, so I'll add the same size white lights above the red ones for the backup. I'll have to cut new holes for those. I've found some nice surface mount small lights to mount above the rear doors for the work lights. More for my "to do" list.

 

[Topzide]

I think in the long run, that would be the best scenario. That way there's no chance of a fried wiring harness and it got to be fixed by tomorrow because of a show! When cutting the new holes, you might be able to use hole saw for ends and a jigsaw with metal blade for the in between. Pop out the other light to run a straight line. If depth is a problem, cut down the jigsaw blade, had to do that many a time!

 

[Dougeye]

I think in the long run, that would be the best scenario. That way there's no chance of a fried wiring harness and it got to be fixed by tomorrow because of a show! When cutting the new holes, you might be able to use hole saw for ends and a jigsaw with metal blade for the in between. Pop out the other light to run a straight line. If depth is a problem, cut down the jigsaw blade, had to do that many a time!

Good suggestions, thanks!