Trailer Wiring

C

Campbell

New member
Hi, I just got a new 16" trailer and am trying to sort out a couple things. They both involve wiring which is not my strong suit!!

First, it has a flat 4 plug and only the drivers side stop lights and blinker work. The tail lights don't light up with the headlights and the pass side lights don't do anything (I did check the pass side bulb and it is fine). What is the best way to troubleshoot this?

Second, it does has electric brakes with just a single wire coming up for it. I know I have to get a brake controller and wire it up.

Lastly, it has an electric winch but doesn't have the control cord. I did put power to it and tried to jump the 4 pin connector.. I think I know which one is ground, I found one pin that had power, the other two don't - how do I approach this?

Thanks
 
First things first - if you're going to be using electric trailer brakes, you're going to need something beyond a flat 4-pin connector. As a minimum, the 4 pin is typically fully occupied just getting the lights to work (taillight, LH turn/brake, RH turn/brake, and ground). That's 4 wires used up, leaving you with no wire for the electric brakes. And some tow vehicles will require 5 wires (or an electronic adapter) just for lights, due to the turn signal and brake lights being on totally separate circuits. Finally, the winch is probably an altogether separate wiring issue, due to amperage requirements far beyond those of a typical trailer lighting connector.
 
what gary said.....

plus, try a quick google search on trailer wiring. you should quickly find some wiring diagrams for the 4 and 7 wire plugs and trouble shooting tips. i would post some links i found when i was figuring out some probs, but i seemed to have deleted them....
 
etrailer.com has a lot of resources that are very helpful... diagrams... instructions.... everything. Greate resource and I have no affiliation.
 
I am towing with a Ford Sport Trac - it didn't have the towing package from the factory but the previous owner installed an OE class III hitch and factory 4 plug connector. The trailer has a 4 plug and a single wire for the electric brakes - I was going to run it up to the controller. The winch is completely separate from the trailer lights - I was running that straight from my battery. Thanks for your help.
 
If you are going to tow with a 16ft trailer, you might want to go this way:

Use a 7 pin connector utilized this way:
1-Ground
2 and 3- Left and Right turn/brake lights
4 Parking/marker lights
5 Power to brakes from the controller
6 Back up lights-optional, but very, very useful
7 fused, constant power to the trailer for the winch (switched).

The actual wiring schematic of the plug is as found on various sites, but the utilisation of the pins is as above.

First order of business, though, is to establish a solid ground (fresh, clean contacts) from tow vehicle (TV) to female receptical, and another solid ground from the Trailer Chassis (TC) to the male plug. All other efforts may be for nothing if the ground does not exist as specified. Recheck the ground for each accessory (lights or brakes), clean the sockets or replace the lights as needed.

My advice is to solder all connections, and smear with a sealer, and then tape or shrink wrap for weather protection. Crimp connectors are for emergencies, and are very bad in the North East.

Put the required time into it and it will pay dividends for years of reliable service.

Good racing.

Bill:024:
 
Also, you need a trailer break away switch and battery ...and I'd consider seriously getting a larger then needed battery, as you have a winch, and they draw some power.
 
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