Trailer Plug Wiring

Contributed By: Michael Baxter

MasterDan@aol.com writes:

>> I have two trailer plugs on the back: a heavy duty 7 spade and a regular large DIN style with 6 pins (plug is about 3/4" dia.). <<

>> The reason that I am bugged is that we got a tent trailer last weekend. I believe it uses all 6 connections as below:
1. left turn
2. right turn
3. stop
4. running
5. constant power (I think w/ ignition on only) for powering refrigerator, trickle charging the marine battery on the trailer, and to power the other goodies if the trailer battery dies out!
6. ground
---- not in that sequence! <<

Dan, I can provide the standardized pin-out for the 7 pin spade (actually 6 spades with one big round center pin) if that's the one you decide to go with.

The industry seems to be settling on the 4 pin flat and the 7 pin spade (called RV plug) as the two standards but, some big 5th wheels require the 9 pin plugs.

Does your tent trailer have separate turn and stop indicators? Pins 1,2 & 3 above are usually combined. Like left turn/stop and right turn/stop. If it does, you'll need an adapter on your Jeep. Here is the industry standard pin-out:

#1 = ground
#2 = brakes
#3 = taillight/clearance
#4 = battery
#5 = stop/LH turn
#6 = stop/RH turn
#7 = aux.

#2 most likely won't be used in your case. I would use largest wire possible on #1 and especially #4. I managed to squeeze an 8 gauge wire on the #4 terminal on the tow vehicle side. It reduces the voltage drop and ensures your trailer battery will charge while you're underway.

I can offer more advice on trailer wiring if you need it. Just contact me via e-mail. Anybody else interested do the same and I'll copy you in on any correspondence.

-- Michael Baxter
From Reno, NV USA on 31-Mar-1997