[Blk88GT]

Is there a fuse I have to install somewhere to get the auxillary lights to work in my enclosed race trailer?

Any help would be appreciated.

 

[LMJD]

You should have a constant hot terminal in your original truck trailer wiring, that would be the one to use.

 

[MarkEkberg]

Ford fro some reason does not keep the 12V wire hot with the ignition off. I had to supply a hot lead for this.

If the truck is on and you do not have power check the fues box under the hood.

 

[MOUNTAINMAN444]

You will either have to run another wire that you can hook up constant hot (don't forget to install an in line fuse) or you can put a battery on the trailer to run the lights. This way you can have lights inside wheather it's hooked to the truck or not. If you install a battery you can hook up the switched hot wire in the plug to it to help keep it charged while you are driving.
Joe

 

[Blk88GT]

Great info guys, thank you! I'll test it out when I get some time.

 

[fastzr1]

I have a Pace enclosed car hauler and my 12V interior lights only work when the lights are turned on in the truck. It took me a bit to figure it out, but it doesn't matter if the truck was on or off. I don't like turning the truck lights on to use the 12V interior trailer lights so I may try the above battery idea.

 

[tomshep]

I have a Pace enclosed car hauler and my 12V interior lights only work when the lights are turned on in the truck. It took me a bit to figure it out, but it doesn't matter if the truck was on or off. I don't like turning the truck lights on to use the 12V interior trailer lights so I may try the above battery idea.

That doesn't sound right. I have a friend with a Pace and his works as described above. You might want to verify there isn't a wire crossed or something in the plug. Are you close enough to have the dealer check it?

Tom

 

[Bill1013]

If you have a small breakaway battery, replace it with a larger one, then hook your lighting up to it . The battery should charge again when hooked up and traveling.

 

[ammayernick]

Hey Guys. I ran into this problem a couple of years ago with my trailer. I could not believe that Ford did not have the wires in their harness already so I did some checking. As an electrical contractor, I startyed tracing the wires up the frame towards the front drivers side, up the fender well to empty plug connectors at fuse panel. According to Ford Technical Service Publications(manual), Ford made(as an option) a trailer relay box which plugs in directly behind and attached the fusebox towards the firewall. The relay box plugs right into the existing harness without the running of new wiring. It will make one wire constant hot and one switched hot for your trailer brake battery charger. Or you can switch the wires to how ever you like at the trailer connnector. The Ford parts guy had no idea what I was talking about. If you need the part numbers, please reply back and I will have to try to find the invoice or check the unit for a part number. Hope I was not too late in my reply. Good Luck!

Andy

 

[Moose122]

So my question is how you you set it up to runt he 12V Aux power to the battery on the trailer to charge it?

 

[Blk88GT]

I'm doing some wiring in the trailer this week, but I suspect I can take the feed for the already installed lights and run that to the two batteries I'm putting in, THEN go to the lights.

 

[acade]

I have a Pace enclosed car hauler and my 12V interior lights only work when the lights are turned on in the truck. It took me a bit to figure it out, but it doesn't matter if the truck was on or off. I don't like turning the truck lights on to use the 12V interior trailer lights so I may try the above battery idea.

did you ever figure out what the problem was...I just bought a 14ft enclosed trailer, and have the EXACT same problem, interior light works only when truck lights are on, and doesn't matter if key is on or off.....any success in figuring this out?

 

[Blk88GT]

acade, mine works exactly the same. I haven't had time to wire up any batteries, so I need to turn the truck on to get power in the trailer. I believe this is expected behavior.

 

[SilveradoHauler]

My F450 came with factory installed 7 pin trailer wiring and plug. As per standard wiring for 7 pin connectors, one pin is 12V for trailer power and for charging the trailer batteries while underway. This is a 30 amp circuit, and has a fuse position in the engine compartment relay box for this fuse, and it is labeled as such. But, Ford did not put a fuse in, so to get power I had to simply plug in a 30 amp fuse.

So if you have a factory installed 7 wire plug, look for a missing fuse. Otherwise, do some wiring, don't forget to fuse it!!!

Funny story, when I picked up my new 34 ft. gooseneck horse trailer, I did not check the battery wiring (it has two large house batteries for the living quarters.)

A few days after the 1000 mile round trip, I was wringing out the wiring, no power from the truck. Fuse blown. Hmm. Checked trailer wiring, then went to the battery compartment. Dummies at the trailer builder wired the batteries positive ground!!!!! Good thing the truck supply was fused, otherwise I would have blown the alternator.

 

[acade]

acade, mine works exactly the same. I haven't had time to wire up any batteries, so I need to turn the truck on to get power in the trailer. I believe this is expected behavior.

yeah, I guess it is a safety mechanism so you don't run your battery down by forgetting to turn the light off

so, my trailer stays parked...its like my mobile garage, so I needed the light to work even when not plugged into the truck...so I wired the light directly to the trailer battery last night...so once it runs out of juice, I'll just plug the trailer up and let the truck recharge the trailer battery when needed

 

[Pararescue1974]

I have a 2017 F350 Superduty, Problem i have is that the interior lights inside my cargo trailer are on one minute off the next ive check the fuses I assume are for the trailer but its unclear and nothing is blown out is there a relay thats getting hot and tripping like i said there is no pattern as to when it works or doesnt. also its not the trailer I hooked it to another truck and works fine