6 pin plug replacement?

[Ol 54']

Looking to replace a 6 pin plug on my 5th wheel. Now what I have done was strip all 6 wires on the old plug thus using a meter, I would go from say the white wire and trying to find resistance to the female termnal, well I am finding resistance on a couple of the terminals? I would think there would be 6 separate readings. The old plug is a sealed one with no screws to take it apart. I just don't want to take the old plug apart and have 6 wires without a clue as to where they terminate. I guess I could just cut the plug a little closer to determine where they go.

 

[Charles in Aus.]

You could determine which wire does what from the vehicle socket . Just work backwards, look for voltage when operating indicators , brakes and clearance lights in turn , transfer that position to the plug and draw yourself a diagram .
The resistance values you are getting probably point to a short and break somewhere in the cable end or plug .

 

[wore out]

Looking to replace a 6 pin plug on my 5th wheel. Now what I have done was strip all 6 wires on the old plug thus using a meter, I would go from say the white wire and trying to find resistance to the female termnal, well I am finding resistance on a couple of the terminals? I would think there would be 6 separate readings. The old plug is a sealed one with no screws to take it apart. I just don't want to take the old plug apart and have 6 wires without a clue as to where they terminate. I guess I could just cut the plug a little closer to determine where they go.View attachment 111282

First of all, you have a SEVEN terminal plug.

It's NORMAL to find a degree of continuity between many of the terminals as all the functions are tied together on one side as they share a common ground, electric brakes, tail lites, right and left turn signals (which double as brake lites), and backup lites.

Here's some diagrams, but no guarantee your cable has standard-color wires!

 

[caterpillar guy]

There should be a screw in the side of the plug or the screw holding the wire into the plug and they come apart. Slip endways over each other to come apart. I have seen the wires individually crimped into the pin crimp so you had to cut each wire loose on those. Top or the one with the raised tab should be ground with the white wire then black and brown on each side from white and green and yellow for the next apir below that and red on the bottom. Blue is in the center. Green and yellow are right and left turn and depending on how your wired can also be the brake wires for a 3 wire set up other wise the red is brakes. Black and brown are marker and tail lights . The blue wire in the center has now been used for the ABS system on trailers. I used it foe my blinky light for over size work. Before the ABS and my trailers didn't have ABS on them. Thhis is all dependent on your particular wiring on both trailer and truck.

 

[MarkB_MI]

Just cut the old plug off. Then you'll be able to read continuity between the severed leads and the contacts. As long as the plug is connected to the trailer you're going to read continuity across the different contacts because they're connected via the lighting and brakes. Not to mention you'll blow the fuse on your meter when you hit the battery lead.

Note that the color coding is very consistent, so you should be able to go by the illustration provided by Wore Out.

 

[jniolon]

a good online source is etrailer.com. lots of good tech stuff, wiring diagrams and videos and replacement parts like you need. You can bend a Visa card very badly as you browse the goodies... stay away from the "ADD TO CART" button

etrailer.com

 

[Loosehandle]

You could determine which wire does what from the vehicle socket . Just work backwards, look for voltage when operating indicators , brakes and clearance lights in turn , transfer that position to the plug and draw yourself a diagram .
The resistance values you are getting probably point to a short and break somewhere in the cable end or plug .

Cut the wires off old plug and leave a little insulation for reference.

 

[BarnyardEngineering]

Got a jump pack? White wire is supposed to be ground, and black is supposed to be the charge line for the house/breakaway battery. Clamp it in the negative clamp of your jump pack. Clamp a nail in the positive, and use it to probe the other wires and see what lights up.

There are a couple of different color schemes used, but it doesn't hurt to verify by probing. By the looks of the picture you should be using the RV scheme.

 

[Blackhole49]

You don't say what the issue is causing you to start this whole process. I'm guessing something not working. If it isn't too late; clean a spot on your trailer frame and hook a jumper cable from the frame to the negative on you battery. Plug the 7 pin connector back in and see if things start working. My 91 24' Dutchman still has the original plug and wiring. When one light goes out it is a bad bulb or connection. When multiple issues occur it is almost always a bad ground.

 

[Jim.ME]

Just cut the old plug off. Then you'll be able to read continuity between the severed leads and the contacts. As long as the plug is connected to the trailer you're going to read continuity across the different contacts because they're connected via the lighting and brakes. Not to mention you'll blow the fuse on your meter when you hit the battery lead.

Note that the color coding is very consistent, so you should be able to go by the illustration provided by Wore Out.

I agree, color coding should be consistent to either the 7 traditional or 7 RV pictures wore out posted. I have found some of those molded cords that were not. On an existing trailer plug I start by verifying color to function position and write them down for reference. If the colors match one of the standard configurations good, if not I know it upfront.

 

[Ultradog MN]

Looking to replace a 6 pin plug on my 5th wheel. Now what I have done was strip all 6 wires on the old plug thus using a meter, I would go from say the white wire and trying to find resistance to the female termnal, well I am finding resistance on a couple of the terminals? I would think there would be 6 separate readings. The old plug is a sealed one with no screws to take it apart. I just don't want to take the old plug apart and have 6 wires without a clue as to where they terminate. I guess I could just cut the plug a little closer to determine where they go.View attachment 111282

I just went through this myself.
Had to do a bunch of repairs to my trailer lights. As was said, check your grounds!
Several of mine were corroded so no blinky.
I bought this grease at a big (semi) trailer place and used it on Every connection and all the grounds.
I also remembered the cap on the factory plug on my Chevy has a wiring diagram on it which made it easier. Check to see if yours is similar?
Lastly, the holes for the wires going into the lights are a a big source of water infiltration.
So I used this pucky that electricians use. I used it 13 years ago when I last did a light rehab on the trailer and most of it was still intact and effective but easy to dig out with a screwdriver to get new wires pulled into the light pockets. Get it in electric department at the big box home store.

Lastly, I bought a new breakaway kit and installed that. Got a trip coming up and don't want the DOT pulling me over somewhere in the middle of Kansas without it.

 

[Charles in Aus.]

I bought a new car some time ago , the clearance lights on my trailer would not work . I immediately blamed the car's trailer harness , couldn't find a problem , had it checked by an auto electrician who said all was well .
I had forgotten that at the same time I had wired in a new , out of the packet LED licence plate light. It was faulty ! The wire code was reversed, black for positive , red negative . To add to the complexity the car had self resetting breakers rather than fuses , so each time the ignition was turned off and on the car appeared normal .It took me three attempts and a full trailer rewire to find and remedy the problem .
Don't trust new components completely.

 

[John T]

When I had no diagrams or color codes I drug out a 12 volt battery and my Simpson 260 and figured it out the hard way it’s not rocket science. On those 7 pole round connectors I’ve seen sone wired eithe the center round pin for backup lights and others used that for 12 volt aux power even if it wasn’t standard or correct. I use standard wiring and if the trailer is wrong I correct it. Good tight clean shiny connections then use dielectric grease works for me. For terminals I crimped and soldered, connections then cover with heat shrink and liquid elec tape never had a problem. Of course many problems are due to poor grounds !!!!

PS I hated those old round 6 pin horse trailer plugs grrrr

John T. Owned many trailers and rv s so been there done that and got the T Shirt

 

[m16ty]

Lots of times even factory wiring on new trailers is junk. If I go to having much lighting issues at all I will rip it all out and start over. Often that is the easiest solution than to try to keep patching junk wiring.

For the plug ends, I just buy a plug that is factory wired and sealed with a length of cord already attached. Then I have a waterproof junction box that the cord terminates into and branches out from there. I feel those plugs don’t give you enough room inside for the connections and they are hard to keep sealed up. That’s why I just buy a whole new cord that is factory sealed and don’t fool with just replacing or fixing the plug.

 

[BarnyardEngineering]

Got a jump pack? White wire is supposed to be ground, and black is supposed to be the charge line for the house/breakaway battery. Clamp it in the negative clamp of your jump pack. Clamp a nail in the positive, and use it to probe the other wires and see what lights up.

There are a couple of different color schemes used, but it doesn't hurt to verify by probing. By the looks of the picture you should be using the RV scheme.

I guess I got a little ahead of myself in the editing the other day, and made a bit of a word salad...

To be clear:
1. Clamp the WHITE wire ONLY in the negative from your jump pack.
2. Clamp the nail in the positive from your jump pack.
3. Probe the other wires (except black, unless you can't find a function) with the nail to see what lights up.

 

[m16ty]

When I had no diagrams or color codes I drug out a 12 volt battery and my Simpson 260 and figured it out the hard way it’s not rocket science. On those 7 pole round connectors I’ve seen sone wired eithe the center round pin for backup lights and others used that for 12 volt aux power even if it wasn’t standard or correct. I use standard wiring and if the trailer is wrong I correct it. Good tight clean shiny connections then use dielectric grease works for me. For terminals I crimped and soldered, connections then cover with heat shrink and liquid elec tape never had a problem. Of course many problems are due to poor grounds !!!!

PS I hated those old round 6 pin horse trailer plugs grrrr

John T. Owned many trailers and rv s so been there done that and got the T Shirt

I know people that purposely wire their plug different to keep people from asking to borrow their trailer. Of course they will still ask to borrow it, they will just pull it without lights or brakes.

 

[Ol 54']

Well got the 6 pin plug all back together and she works fine, the only thing I don't understand is why the L/H turning light turns on and off real fast like weather it is connected to the truck or not..

 

[m16ty]

Well got the 6 pin plug all back together and she works fine, the only thing I don't understand is why the L/H turning light turns on and off real fast like weather it is connected to the truck or not..

How does it flash fast when not connected to the truck?
Usually a fast flash is caused by a heavier than normal load with a contacts flasher. Does your truck have a flasher with contacts or it it a solid state flasher?

 

[Scott 730]

Well got the 6 pin plug all back together and she works fine, the only thing I don't understand is why the L/H turning light turns on and off real fast like weather it is connected to the truck or not..

7 pole RV plug.

 

[Jim.ME]

Well got the 6 pin plug all back together and she works fine, the only thing I don't understand is why the L/H turning light turns on and off real fast like weather it is connected to the truck or not..

You have what is called a 7 way or 7 blade plug. There is a 6-pin plug which is different than what you have, it has round pins like the plugs used on semi-trailers, not flat blades as you have.

It seems like you mean your truck blinks fast on the left-hand side with or without the trailer connected, but your wording sounds like you are talking about the trailer. If you have dual contact bulbs (parking and turn signals in one bulb like a #1157) I have seen a filament break and cross onto the other filament and make the fast blink. I would say check the bulbs