TRiGGeR605

Hey guys, I have a 21ft enclosed trailer and I can only run the dome lights/flood lights when my truck is hooked up and lights are one. I recently installed LED lighting to replace all the stock bulbs. I'd like to be able to run the lights while being disconnected from the truck.

My first thought is to mount a battery in the trailer and tap into the power just before my light switches. If I do this, once my truck is hooked up, is there any possibility of the current returning to the battery and harming it?

Would it be better to tap into the line after the switch?

Is there a better way to do this?

Thanks

raisin

Why don't you set it up like an RV trailer? Mount deep cycle battery on trailer. Since you have trailer brakes you are using a 7-pin connector. So wire from the 7-pin hot wire on the trailer to the battery to charge new battery while on the road. You can use a battery charger to top off new trailer battery when you get home.

You would unhook any dome/flood light from running/tail light circuit and hook to battery circuit using proper fuse/circuit breaker.

smokeywren

What raisin said.


Study the wiring diagram for the trailer plug near the back bumper on any 2011-up F-150 or F-250 that has the factory towing pkg. Then be sure your trailer plug on the back of the pickup is wired the same way, with the same fuses and relays.


Then find a wiring diagram for any RV trailer that has brakes and one or more on-board 12-volt batteries and a 12-volt power distribution box (breaker and fuse box). Pick and choose which of the RV circuits you want for your cargo trailer. For example, my TT has indoor 12-volt light circuits, plus a switched outdoor 12-volt porch light, plus another switched 12-volt light in the "basement". And one of the wires in the trailer plug is a 12-volt "hot" wire that's used to charge the batter(ies) in the trailer when you are towing the trailer.


Your cargo trailer probably also has an itty bitty 12-volt battery on the tongue. That battery is used only to lock the electric brakes on the trailer if the trailer becomes disconnected from the tow vehicle. If you install bigger 12-volt batter(ies) in the trailer, then you need to rewire that disconnect system so it uses the power from the bigger batter(ies) and no longer uses the itty bitty battery.

I won't attempt to explain how to wire it all up. If you don't understand how to read wiring diagrams enough to DIY, then you should have a trailer or RV shop do it for you.

Boulevard

No, it will not harm your truck battery but what it may do is burn out the thin gauge wire that goes from the truck to the trailer battery or you may pop a lot of fuses.


Your truck and trailer is not meant to have a battery on this circuit so the wires are sized for low current draw. If you throw on a battery onto the lighting circuit the truck will try to charge the trailer battery through the lighting system and the result will probably be a lot of burnt wire and popped fuses.


I would completely severe the outside lights from the inside lights and only run the inside lights from the battery. This way there is no way that these 2 systems can charge each other. All you have to do is keep the inside light battery charged using booster cables or a battery charger.

TRiGGeR605

Sounds good, I think I seen a diagram before on the wiring. I only need to light up the trailer for short amounts of time, less than 30 mins at a time. I'd only be using 5 lights when doing this and I just switched them all to LED's. I was thinking about getting a small lawn mower battery to power the trailer. Think that would be good enough?

raisin

That sounds like a good idea. Led's won't draw much and battery will recharge quickly. You could forgo the wire to truck and recharge with battery charger when you get home.

tomb1269

You could also invest in the Diehard jump pack that is about $150, and set it up to use as a battery. The advantage would be that you can charge it in the house or garage and use it for whatever you need. The reason behind the Diehard is unlike nearly every other jump pack under $250 it is the only one with a float charger and therefore you can plug it in and leave it, where the others once they are fully charged you have to take them off charge.
http://www.sears.com/diehard-platinu...1&blockType=G1
I am looking at possibly wiring my trailer to provide 12V power when connected to truck (i.e. center pin on a 7pin plug) to be able to charge the jump pack while driving as well. (my trailer only has 4pin connection, I am thinking to convert to 7pin to get 12volt source)

Frank McGrath

My trailer battery is always dead. I am running a hot cable from the battery to the rear bumper of my '14 Supercrew. Then, using industrial connectors, making a jumper to run from the bumper to the camper battery. This will do away with using jumper cables to use the electric Jack to hook up the trailer. Sounds like a lot of unneeded labor, but it's better than using my 40 foot jumper cables.