Quick question about trailer wiring

   / Quick question about trailer wiring #1  

jmc

Elite Member
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Jul 21, 2003
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SW Indiana
Tractor
Ford 1920 4x4 (traded in on Kubota). Case 480F TLB w/4 in 1 bucket, 4x4. Gehl CTL60 tracked loader, Kubota L4330 GST
Are all 7 wire male trailer connectors standard? ie, if I used someone else's trailer, would my plug fit it?
 
   / Quick question about trailer wiring #2  
It should, yes. Unless it was some unique application. There used to be a "flat pin" and a "round pin" connector, but that has pretty much become a standard "flat pin" now, for light duty, RV and non-commercial equipment. I think Ag and commercial equipment still used the "round pin" connectors, but I've been out of commercial trucking for quite some time now.

You also have to assume that whomever wired the plug, followed the "standard" wiring schematic.
 
   / Quick question about trailer wiring
  • Thread Starter
#3  
Slowpoke Slim, thanks for the quick reply.

Turns out, mine is a 6 pin with round contacts, from around 20 years ago. Looks like more recent contacts are often "blade" type, which throws another variable in the mix.
 
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   / Quick question about trailer wiring #4  
Slowpoke Slime, thanks for the quick reply.

Turns out, mine is a 6 pin with round contacts, from around 20 years ago. Looks like more recent contacts are often "blade" type, which throws another variable in the mix.

Save your self frusteration down the road by rewireing with 7 pin. Yes, all 7 pins should be the same.if wired by someone who knew what they were doing.
 
   / Quick question about trailer wiring #5  
Save your self frusteration down the road by rewireing with 7 pin. Yes, all 7 pins should be the same.if wired by someone who knew what they were doing.
Yes, move to the standard 7 flat pin "RV style" connector if you are going to mess with anything. Dont count on the old wire colors to be standard though.

Trailer Wiring Diagrams | etrailer.com
 
   / Quick question about trailer wiring #6  
We have a 1975 built boat trailer with a six pin round connector. 6 Pole Round Trailer End Plug | etrailer.com I could not get it working, luckily we brought some magnet mount LED stop/tail/turn lights.

4 pin is no brakes, 5 pin adds backup lights/backup brake lock. 6 and 7 pin added a line for a brake controller.

You can buy 6-7 pin adapters. But for not much more you can simply rewire the trailer to 7 pin, which is the standard round connector on most cars and trucks with standard plugs in their hitch.
Replacing 6-Way on Trailer With 7-Way Connector | etrailer.com

We brought the trailer to a specialist shop and had everything updated. Replaced tires, brake controller, added LED lights, moved the tail lights higher on the trailer, 7 pin harness, breakaway lock, etc.
 
   / Quick question about trailer wiring #7  
If your towing vehicle(s) is/are wired per the standard provided by Fallon then any of the adapters used with somebody else's trailer cord will automatically work if the trailer is wired to the standard. Pays to check it all before hitting the road. I carry all the various adapters in my pickup along with a short cord, that matches my 7 pi, with clip leads and have the standard laminated in plastic. Ready for any combination!
Ron
 
   / Quick question about trailer wiring #8  
They should be the same.
Sometimes the "white" ground wire/pin is not used, and the return path is through the trailer frame, and vehicle ball hitch, vehicle receiver, to vehicle frame, instead of this wire/pin. If ground pin is used on the trailer, typically the associated white wire will only be run a short distance from the connector and land on a bolt or be screwed into the trailer's frame.
So, if it's not used, and the trailer's frame/ball hitch is being used for the path, make sure the vehicle's ball hitch mount (male) has good contact with the vehicle's receiver (female) and paint, rust, or warning labels don't prevent good metal to metal contact that is needed for the return "ground" (-) path.
 
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   / Quick question about trailer wiring
  • Thread Starter
#9  
Thanks All, for the feedback. Time to upgrade to that 7 pin and a glovebox full of adapters.
 
   / Quick question about trailer wiring #10  
Save yourself the time, your trailer lights will stop working the minute a State Trooper is behind you anyway. :)
 
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