No interior lights in trailer - everything else is fine

[henitsl]

I own an 05' w/o big trailer package. I hooked up an Interceptor brake controller with a Nissan connector harness to the brake controller's 4 bare wires. (I bought this five wire Nissan harness directly from my Nissan dealer for $16). One end has a fancy plug which connected directly into the truck's connector under the steering wheel). The other end has five bare wires which go to the brake controller; four of which I connected to the brake controller. One blue/red wire left alone.

All other lights and brakes work perfectly, except I can't turn on the interior lights of the trailer. Trailer dealer assured me they worked when they plugged it to their Dodge truck before delivery. There is one wire on the Nissan harness which is left empty (blue/red) which the owner's manual says goes to the Illuminate the Brake Controller). I'm wondering if this goes anywhere else?

I'm told by the trailer dealer that the interior lights of the trailer should work when I turn on the parking lights of the truck. I've tried every combination w/o success.

Can anyone help me getting the interior trailer operational?

[BuckyBadger]

If the tail lights work the inside lights should work...thats how mine is. I think the trailor is the problem. You can put 12v into the harness of the trailor and see if they come on. or hook it to someone elses truck. You should start at the lights and work your way back to the front harness to find the bad connection.

[Derwud]

The battery is dead or dis-connected on your trailer...

Year, make, and model of trailer?

[BuckyBadger]

Is it a trailor or a travel trailor???? Did you plug it into land power?

[henitsl]

Its a brand new Road Force trailer from Wells Cargo, which I'm converting to haul motorcycles. I'll try connecting a 12V power supply to the trailer's harness and see what that does.

I'll also check the fuse inside the engine bay. Are there supposed to be two fuses or one?

Thanks guys, I'll keep working on this problem.

Les,

[henitsl]

I checked the engine bay fuse box.
There is a larger brown relay, and a smaller blue one.
But there is a slot open for another relay? I wonder if something should go here. I'll go to my Nissan dealer and ask them. Hopefully, this may be the problem solver.

Les,

[henitsl]

A local Nissan dealer checked my VIN number, and did not find any recalls. I checked the 7 pin outlet, and found the center connection (yellow) is not hot under any circumstances. I checked the engine bay fuse box, and saw a larger brown relay and a smaller blue relay. There was an empty slot for the same larger brown relay; in which I noticed yellow wires coming from that empty slot. I have a hunch that another identical brown relay should go here to activate the yellow wire for the 7 pin outlet. According to schematics, this yellow center pin on the hitch outlet is used to run accessories in the trailer.

I'm hoping a second relay will do the trick. What does anyone think about this?

Thanks, Les,

[Sammy Sandbag]

Not sure if it helps, but my '04 non-BT required an additional relay to operate the trailer running lights. Brake and turn worked fine without it.

[loufish]

With all the tow relays installed, you only get 12v back to the trailer plug with the ign on, that keeps the truck battery from getting drained if you leave the trailer plugged in for any length of time...If you have a 12v battery on the trailer and the lights still don't work then the battery's dead or it another trailer issue, not the truck.

[henitsl]

The number of relays is my issue at the moment. Can anyone tell me how many relays there should be in the engine bay compartment? I have a large brown, and smaller blue now. Do I need a second large brown relay; since there is a slot for it?

The trailer does have a new battery, which I will check also.

Seems each different model year of the Titan has different relay configurations.

Thanks,

Les,

[Buildwonder]

You should have 2 brown relays. If you have an empty relay receptacle then you're missing one. There will be empty holes, but if there's something to plug in to showing then you need the additional relay. Do a search for the relays on here. I recall seeing one of the members posting pics of the completed relay box. That should help you.

[tbourdaux]

I am having the same problem with my Big Tow 05. Interior Lights will not work while towing. Can't even get 12 volts on the Pin with a test light. I too have both relays (1 brown and one blue)

[young dank]

Originally Posted by henitsl

I own an 05' w/o big trailer package. I hooked up an Interceptor brake controller with a Nissan connector harness to the brake controller's 4 bare wires. (I bought this five wire Nissan harness directly from my Nissan dealer for $16). One end has a fancy plug which connected directly into the truck's connector under the steering wheel). The other end has five bare wires which go to the brake controller; four of which I connected to the brake controller. One blue/red wire left alone.

All other lights and brakes work perfectly, except I can't turn on the interior lights of the trailer. Trailer dealer assured me they worked when they plugged it to their Dodge truck before delivery. There is one wire on the Nissan harness which is left empty (blue/red) which the owner's manual says goes to the Illuminate the Brake Controller). I'm wondering if this goes anywhere else?

I'm told by the trailer dealer that the interior lights of the trailer should work when I turn on the parking lights of the truck. I've tried every combination w/o success.

Can anyone help me getting the interior trailer operational?

dawg, your trailer interior lights are controlled by the trailers battery. your truck recharges that battery. your trailer lights should come on even if the truck is not hooked up if your battery is charged

[young dank]

Originally Posted by henitsl

The number of relays is my issue at the moment. Can anyone tell me how many relays there should be in the engine bay compartment? I have a large brown, and smaller blue now. Do I need a second large brown relay; since there is a slot for it?

The trailer does have a new battery, which I will check also.

Seems each different model year of the Titan has different relay configurations.

Thanks,

Les,

depends, 06 and later needs too blue relays for LH & RH lights