5th Wheel electrical connection to 7 wire trailer connection

[merc1118]

While backing up my 2017 3160RL, the wire to the 7 pin round connection to my truck ripped apart from the junction box on my Morryde 5th wheel. The wire got wrapped around my trucks trailer hitch and ripped apart while making a tight turn. The wires are OK, but I am having difficulty matching colors on the 5th wheel side to the wires going to the truck side. Anyone have a diagram or link to a web site that has this info. I checked the Morryde installation manual, but it doesn't cover electrical connections.

Thanks.

Larry and Loralei
2012 Chevy Suburban 3500 Duramax
2017 3160 RL

[h2ojocky]

https://www.google.com/search?q=7+pi...hrome&ie=UTF-8

Hope this helps!

[rohrmann]

Are you towing your fifth wheel with a Suburban? Maybe that's why you ripped your cable loose.

[scottz]

Bargman 57 diagram

[scottz]

Table version. And I would also like to see the 5th wheel hitch on your Suburban!

[merc1118]

OK, here's whats going on:

Green to green, OK

Brown to brown, OK

Yellow to yellow, OK

Light blue: 5th wheel has a black wire and light blue wire connected together along with the remnants of the light blue wire from the 7 pin connector, so I'm OK with light blue.

Red: 5th wheel has 2 disconnected reds with no remnants from the 7 pin connector. One of the 5th wheel reds is heavier gauge than the other. Does the red from the 7 pin connector join up with the 2 reds from the 5th wheel?

White: 5th wheel has 3 white wires connected loosely together, looks like there's room in the connector for the white wire from the 7 pin connector. I'm going to go with this unless someone has a better idea.

There is a black wire and a dark blue wire from the 5th wheel that are connected together with no room for any other wires. I think they might be part of the emergency trailer brake system.

Black wire: There are no other black wires coming from the 5th wheel, so I'm not sure what to do with the black wire from the 7 pin connector.

[merc1118]

Me too! Silverado...

[merc1118]

Thanks for the replies. What I'm seeing is standard 7wire to 7 wire connections. There are more than 7 wires coming from the 5th wheel. Makes for a bit of confusion. I am at a park with some other Montanas, so hopefully someone will let me open their junction box to take a look.

[scottz]

Originally Posted by merc1118

OK, here's whats going on:

Green to green, OK

Brown to brown, OK

Yellow to yellow, OK

Light blue: 5th wheel has a black wire and light blue wire connected together along with the remnants of the light blue wire from the 7 pin connector, so I'm OK with light blue.

Red: 5th wheel has 2 disconnected reds with no remnants from the 7 pin connector. One of the 5th wheel reds is heavier gauge than the other. Does the red from the 7 pin connector join up with the 2 reds from the 5th wheel?

White: 5th wheel has 3 white wires connected loosely together, looks like there's room in the connector for the white wire from the 7 pin connector. I'm going to go with this unless someone has a better idea.

There is a black wire and a dark blue wire from the 5th wheel that are connected together with no room for any other wires. I think they might be part of the emergency trailer brake system.

Black wire: There are no other black wires coming from the 5th wheel, so I'm not sure what to do with the black wire from the 7 pin connector.

The white wire is probably ground; that is why several of them are connected together.

The black and dark blue wires probably connect to the 12V feed from the truck. One goes to the trailer battery, the other to the break away switch (but I'm a little confused with the light blue wire). If you have a volt meter you should be able to find which wire connects to the trailer battery (or you could do a spark test!).

I would:
1: identify which trailer wire goes to the trailer battery (probably black); so you can be careful with it.

2: identify which trailer wire goes to the ground (probably white); use an ohm meter for this.

3: use a 12V source (perhaps the wire identified in step 1) to identify what the other wires are for. The left, right, and tail will be obvious. The brake will not be so obvious.

Do you have back up lights? If so, one of the wires if for them.

Sorry I can't be much more help, but I'm sure you will figure it out.

[merc1118]

Thanks everyone for the help. Turns out the heavy gauge red wire was my 12V, so black on the 7 wire connection goes to it. All the other wires follow standard color codes. Making a quick run to a local hardware store in the morning to pick up some wire connectors to hook it back up. Scott's information and inspection of another Montana owners 5th wheel connections made something that seemed difficult very easy.

Think from now on I'll disconnect the cable from my truck before doing any tight backing.

[Phil P]

Hi

This is the problem with any 5th wheel trailer that’s why the 18 wheelers have the electrical cable on a spring so it can stretch out when the rig is in a tight turn like backing up to a loading dock where the TV has to be right angle to the trailer so traffic is not blocked and then retracts so it doesn’t get caught on something causing the problem you have.

This is where the in bed receptacle is an advantage it would be easy to put a bungee cord on your cable so it will do the same thing as the big trucks.

However I have a very great dislike for the in bed receptacle because of the way I use the TV when not towing.

I now have 100,000 miles on the Montana and I am on my second cable and have done a number of repairs.

Phil P

[WeBeFulltime]

Originally Posted by merc1118

Think from now on I'll disconnect the cable from my truck before doing any tight backing.

I would avoid ANY backing that would be tight enough to damage your wiring. Any backing that tight is putting WAY TOO MUCH stress on your axles and tires!

[merc1118]

Thanks again. Good help and good advice. All wired up and ready to roll.

[prndl]

It sounds like you are connecting to the 7 pin connector on your truck bumper....

If so, you should move it to the inside of the truck bed. All you need is a plug and play pigtail adapter and a hole saw.

[rohrmann]

If not the receptacle inside the bed area, at least a short extension cord to get into the bed area from the bumper receptacle.