Hi all. I am going to add a 105 watt extra reverse light, possibly two of them. They are kinda trashed but still work. and they were free. so why not. My question is, Where would you guys put the relay? under the hood or in the back by the tail lights. I want to put a switch to be able to turn them on sepretly. I do have a trailor harnes witch I think has power lead I can tap into and easy reverse light power for the relay. But were to put the relay so it stays dry. Or under the hood all the power I need and easy to ad a switch. relay dry. But were to get the reverse signal. Is there a place under the dash or the hood to get revese power to run the relay. Any advice would help. thanks

98 f-250LT 4x4

 

I tucked mine on top of the frame at the very back of the truck....I also wrapped the relay harness with a balloon and sealed it with nylon straps, and smeared the contacts with dielectric grease. There is a power wire that you can tap into from your trailer wire harness, and tap into the reverse light feed in the tail light to switch the relay.

 

The Towing Package wiring on my '98 F150 includes back up light function in the rear socket. I was more than happy adding a single Bosch 55W halogen fog light as an auxillary back up light. It was essentially a plug & play installation. There was no need to "tap into the reverse light feed in the tail light" or add a switch, relay, or run wiring whatsoever.

Good luck adding "a 105 watt extra reverse light, possibly two". One word of caution. At 1st I tried another H1 light I had sitting around, happened to be a driving light. The narrow spot beam was virtually useless as a backup light. The wide flood beam of the Bosch fog light is spectacular & radiically improved backing up trailers at nite.

You say "so why not."? IMO 210 watts of "Reverse lights" sounds excessive & is unlikely to be supported directly by Towing Package wiring. Adding a switch, relay, wiring & mounting for 2 sounds like a PITA to install "kinda trashed" lights that might already be on their last legs.

My "advice" would be to check if you have the same Tow Package wiring & utilize it. It may support a single 105W light. If not you may be able to use a lower wattage bulb. All you'd need is to mount it & plug it in, using 1 short piece of wire. I mounted my rectangular light neatly out of the way, under the bumper, on the hitch, by making up a small bracket.

Alternately, if you have this Towing Package wiring you could use the existing back up light line just to switch a relay, then use the heavy Breakaway Battery line to easily power 210W. Sorry, but if you need to have a separate on dash switch & a "98 f-250LT...trailor harnes" is different, I have no "advice".

 

Took me all about an hour to mount, wire, and have good functioning reverse lights using 3" fogs without any hassle. Took all about a few minutes to pull the tail light off and soder (or even easier, use a tap connector) in a wire to run to the relay. Buy a good 30 amp relay with a pigtail at any parts store or 4X4 shop and you're good to go.

 

I mounted the Bosch fog light to the hitch grounding it & connected the short hot wire directly into the existing Tow Package backup light outlet & was "good to go" w/an excellent functioning auxillary backup light.

No trip to "any parts store or 4X4 shop" to buy "a good 30 amp relay" to tuck on top of frame.

No "wrapped the relay harness with a balloon and sealed it with nylon straps, and smeared the contacts with dielectric grease".

No "pull the tail light off and soder (or even easier, use a tap connector)".

No "wire to run to the relay....with a pigtail" or to a dash switch.

Surely utilizing an existing Tow Package (supports 7 pin RV/trailer socket) backup light line & using a modest 55 watt halogen is far less of a "hassle" & provides a very dramatic upgrade.

If a separate switch is needed, so 210 watts of auxillary backup lights can be turned on at any time, you'd need to bypass the Digital Transmission Range (DTR) sensor completely. The DTR is the source of "the reverse signal" it runs on a 15 amp fuse & is only On in reverse w/key in Run position.

 

Thanks for the advice. I plan to take the power off the trailor back up lights. But line has no power when I cheaked it. Were is the fuse so i can cheak it. If its not the fuse
im not sure shat it would be. any Ideas.

 

I want to thank you all for your help. I got it working last night. It was a blown fuse. I tapped off of the back up trailer lights on the harness. and works great. But it is a little narow. so when I can afford it I will take the advice and get 2 wide lights and put them in there. Thanks