Trailer plug question

[Cummings]

The center lug (constant hot) on my trailer plug is dead. I've looked at all the fuses in the fuse box, and they're all OK. Is there another place that there is a fuse, or breaker, that I should look at? The truck is a 2006 3500 with CTD Thanks.

 

[RustyJC]

If you're referring to the factory 7-pin Pollak-type trailer plug, the center pin is an auxiliary pin typically used for back-up lights. The #4 pin is B+ (battery positive).



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Rusty

 

[Blu-meanie]

That's a nice picture, but it's not the way my stuff is wired.

Move the notch to the top and it's good.

 

[RustyJC]

They're wired exactly the same. It depends on whether or not you're looking at the trailer or tow vehicle recepticle/plug, and the front or back side. Look at the right picture you posted - that's the back of the tow vehicle recepticle. The picture I posted is the back of the trailer plug. The notch is where the terminal cover engages on the back side and is the same as the tow vehicle recepticle picture you posted on the right side, except it's a mirror image since the trailer plug is viewed 180 degrees differently than the tow vehicle recepticle. .



If you don't believe me, look at the pin numbers and functions. They're the same. That's what you ALWAYS go by.



Rusty

 

[BIGNASTY]

Trailer Plug

When I first got my truck and TT I hooked up and was going camping. I had never pulled anything behind a pickup before. (had a class 8 trk if I needed anything moved) the flat plug was a real pain in the A** for me had enough one day and went down and bought the sockets and plug - plug pig tale from the Big truck store and installed it I have NEVER, NEVER had a problem from that time. I also have made an adapter so someone else can use my TT that has a flat (RV) plug.

 

[HBarlow]

Gail,

I've read or heard several times in the past that big truck trailer plugs are tougher, more durable, and more waterproof (I think). How are they different from RV connectors?

 

[Prairie Dog]

The center lug is not a constant hot or "aux", it's your B/U lamps. You can see a diagram embossed on the lid for the connector on your truck.

 

[seafish]

Gail,



I've read or heard several times in the past that big truck trailer plugs are tougher, more durable, and more waterproof (I think). How are they different from RV connectors?

HB, The trucker style Pollack 7 connecors use a bullet type, solid brass, round pin that is almost 1 1/2" long to plug into a matching trailer plug. If you buy the good ones, they are made entirely from zinc coated, die cast metal, except for the plastic insert that insulates the connectors from each other. The wires are connexted to the bullet pins by a screw thread directly into the side of the pin. Squeeze in a little dialectric grease, push the stripped wire in, tighten the screw and you are good to go for a LONG time. Also ou can buy the trailer plug that has a HD spring that wraps around the wires where they go into the plug, thus relieving tension from the wires themselves. Simply put, the connection is a lot longer, stronger and thus more stable, then the equivalent RV 7 pin blade type connector. Look at these pictures, and then, even better, look at the prices, because they actually cost LESS then their RV counterparts, especially if you go to a truck supply store like Fleetpride instaed of an auto supply or RV supply store. You can use the thumbnail pics on the links below to see close-ups of the connectors.



Pollak Heavy-Duty, 7-Pole, Round Pin Trailer Wiring Socket - Vehicle End Pollak Wiring PK11720



Pollak Heavy-Duty, 7-Pole, Round Pin, Trailer Wiring Connector - Trailer End Pollak Wiring PK11700



I actually left the factory connector in place, and used one of these --



Valley Fifth Wheel and Gooseneck Wiring Harness with 7-Pole - Dodge with Factory Tow Package Valley Custom Fit Vehicle Wiring V30137



Gooseneck extensions, with the second plug end cut off, to wire a Bullet type, big rig connector on the right side of my bumper while still leaving the oem RV type connector on the left side of the bumper. That way, I can pull my own trailers that are wired with the HD connectors, or if I am hauling someone else, still be able to use the oem flat blade RV type connector without having to use any adapters. Here is a link to a pic of the back of my bumper showing BOTH connectors--



Anyone Line-X'ed the bumpers? - TDR Roundtable



Hope this helps... they are a DEFINITE upgrade.

 

[BIGNASTY]

Gail,



I've read or heard several times in the past that big truck trailer plugs are tougher, more durable, and more waterproof (I think). How are they different from RV connectors?

For one they are made of metal alloy that wont get broken as easy as the plastic RV plugs. The pins are round and seem to fit better than the flat plugs of the RV plugs. the wire connections are better and more insulated from the elements. The Truck plugs are used to hook and unhook trailers many many times a day and still they work. The thing I like about them the most is that the PIG tail from trk to trailer is coiled and doesn't seem to get pinched or drag on the pavement. Mainly its just a very well built ALMOST truck driver proof.

 

[Bob4x4]

When I first got my truck and TT I hooked up and was going camping. I had never pulled anything behind a pickup before. (had a class 8 trk if I needed anything moved) the flat plug was a real pain in the A** for me had enough one day and went down and bought the sockets and plug - plug pig tale from the Big truck store and installed it I have NEVER, NEVER had a problem from that time. I also have made an adapter so someone else can use my TT that has a flat (RV) plug.

Nice... ... ... . I have both connectors on the 94 just haven't done the 3rd gen yet

 

[Bill Stockard]

When my wife and I purchased our first Airstream travel trailer in 1976, it came from the factory with the round pin 7-way plug instead of the blade type. When our mid-70s tow vehicle came from the factory equipped with the trailer tow package, only the wire harness to the rear bumper was furnished without the receptacle. I had to install and connect the 7-way round pin type receptacle to the wire harness matching the wiring to the Airstream plug.



The standardized blade type RV receptacle/plug and standardized wiring came later.



Bill

 

[HBarlow]

HB, The trucker style Pollack 7 connecors use a bullet type, solid brass, round pin that is almost 1 1/2" long to plug into a matching trailer plug. If you buy the good ones, they are made entirely from zinc coated, die cast metal, except for the plastic insert that insulates the connectors from each other. The wires are connexted to the bullet pins by a screw thread directly into the side of the pin. Squeeze in a little dialectric grease, push the stripped wire in, tighten the screw and you are good to go for a LONG time. Also ou can buy the trailer plug that has a HD spring that wraps around the wires where they go into the plug, thus relieving tension from the wires themselves. Simply put, the connection is a lot longer, stronger and thus more stable, then the equivalent RV 7 pin blade type connector. Look at these pictures, and then, even better, look at the prices, because they actually cost LESS then their RV counterparts, especially if you go to a truck supply store like Fleetpride instaed of an auto supply or RV supply store. You can use the thumbnail pics on the links below to see close-ups of the connectors.

Pollak Heavy-Duty, 7-Pole, Round Pin Trailer Wiring Socket - Vehicle End Pollak Wiring PK11720

Pollak Heavy-Duty, 7-Pole, Round Pin, Trailer Wiring Connector - Trailer End Pollak Wiring PK11700

I actually left the factory connector in place, and used one of these --

Valley Fifth Wheel and Gooseneck Wiring Harness with 7-Pole - Dodge with Factory Tow Package Valley Custom Fit Vehicle Wiring V30137

Gooseneck extensions, with the second plug end cut off, to wire a Bullet type, big rig connector on the right side of my bumper while still leaving the oem RV type connector on the left side of the bumper. That way, I can pull my own trailers that are wired with the HD connectors, or if I am hauling someone else, still be able to use the oem flat blade RV type connector without having to use any adapters. Here is a link to a pic of the back of my bumper showing BOTH connectors--

Anyone Line-X'ed the bumpers? - TDR Roundtable

Hope this helps... they are a DEFINITE upgrade.

Seafish,

Thanks for all that good information and links. After looking the photos over carefully I saved the links.

I'd order the male and female ends from eTrailer today and convert mine but I occasionally pull my son-in-law's job site fifth wheels to new construction projects and wiring up both RV and truck style females on my truck seems like a lot of trouble and additional clutter on the truck bed.

Does Pollak make an adapter to allow plugging in RV flat blade male ends to the truck round pin receptacle? I could buy and carry one if they sell one.

I can't use the extension harness you're using to create another female connector because my truck is a C&C. The C&Cs have the wiring harness simply terminated and taped at the rear frame rail when delivered, they don't use the OEM Dodge connector the extension mates to. I have used that extension harness on two previous trucks and like it.

 

[RustyJC]

The center lug is not a constant hot or "aux", it's your B/U lamps.

Yes, as I said in post #2, Dodge uses the center pin (pin #7) for back-up lamps. Unlike the other pin assignments, however, that's not a universal application for every instance where this Pollak connector is used - that's why pin #7 is called an auxiliary pin.



For instance, many motorhomes that tow vehicles equipped with supplemental braking systems will send the brake signal to the towed vehicle's supplemental braking system through pin #2, and the supplemental braking system will send a signal back to the motorhome through pin #7 (the center pin) to illuminate a light on the dashboard display indicating to the driver that the supplemental braking system is engaged.



Rusty

 

[Cummings]

Thanks, guys, you hit it right on the head. I was detecting the wrong pin, but the large 30 amp breaker was bad.

 

[seafish]

Seafish,



Does Pollak make an adapter to allow plugging in RV flat blade male ends to the truck round pin receptacle? I could buy and carry one if they sell one.

HB, I was about to say that you owuld have to make one yourself like I originally did by buying an extra pair of ends and then wiring them together, but I quickly googled "Pollok 7 blade to pin adapter" and look what came up --



Adapter 7 Way (Blade) to 7 Way (Round Pin) Hopkins Wiring 47595



I think that you'll be more then happy by doing the conversion and using the adapter when towing other peoples trailers.

 

[Allnew2Me]

The heavy-duty truck connectors are nice and are less likely to be pulled out than our standard connectors. The only downside I see is that if you use them then you become non-standard. For most this may not be an issue, and you can always make a pigtail to convert if you ever needed to use a trailer with the standard connectors on it.

Another option, although quite a bit more expensive is this clever way of hooking up. They even make the adaptors to convert.



EZ Connector Trailer Plugs - Waterproof, corrosion free trailer plugs

 

[BIGNASTY]

The heavy-duty truck connectors are nice and are less likely to be pulled out than our standard connectors. The only downside I see is that if you use them then you become non-standard. For most this may not be an issue, and you can always make a pigtail to convert if you ever needed to use a trailer with the standard connectors on it.

Another option, although quite a bit more expensive is this clever way of hooking up. They even make the adaptors to convert.



EZ Connector Trailer Plugs - Waterproof, corrosion free trailer plugs

I dont know about having the plug held in Magnetically would hate to have that thing come out at the wrong time at least on the 7 way plug used on trucks the female end of the connection has a detent on the cover and when the male is installed the detent fits into a matching slot in the male. And the cover has a pretty good spring on it to hold it down. Another thought would be if you need to have both kind of plugs wire another on the other side of the lic. plate I have a small version of the same Truck plug on the other side of the Lic. plate I have it wired up for some lights that I installed at the back of the TT so when I need to back up at night im not doing it in the dark. The reason for the separate plug is that the lights are very strong and I didnt want any electronic feed back or any kind of problem when I turn on the lights. I guess I could have the wife get out and watch but God Bless Her she just doesn't get it when I tell her if she cant see my mirrors I cant see her most spotters dont.

 

[HBarlow]

HB, I was about to say that you owuld have to make one yourself like I originally did by buying an extra pair of ends and then wiring them together, but I quickly googled "Pollok 7 blade to pin adapter" and look what came up --

Adapter 7 Way (Blade) to 7 Way (Round Pin) Hopkins Wiring 47595

I think that you'll be more then happy by doing the conversion and using the adapter when towing other peoples trailers.

Seafish,

Thanks for your help but I don't think that adapter is what I would need. I looked carefully at the adapter in the link but it adapts in the wrong direction doesn't it?

In order to convert my truck and fifthwheel to seven pin round big truck connectors then have the capablity to pull someone else's trailer with a seven pin flat blade male connector I would have to have a "Adapter 7 Way (Round Pin) to 7 Way (Blade)" right?

I searched through the remainder of the adapters on eTrailer.com and couldn't find the reverse adapter.

 

[seafish]

Seafish,



Thanks for your help but I don't think that adapter is what I would need. I looked carefully at the adapter in the link but it adapts in the wrong direction doesn't it?



In order to convert my truck and fifthwheel to seven pin round big truck connectors then have the capablity to pull someone else's trailer with a seven pin flat blade male connector I would have to have a "Adapter 7 Way (Round Pin) to 7 Way (Blade)" right?



I searched through the remainder of the adapters on eTrailer.com and couldn't find the reverse adapter.

HB, so sorry... you are absolutely right, the adapter I linked to IS the wrong direction for what you want to do. I also cannot find one that has the correct plug and socket ends which is likely why I made one myself years ago after I upgraded the blade type socket on my old 93 W250 dually with a pin type 7 way connector . Since I did not do the dual plug set up like I have on my truck now, I needed an adapter, like you might need, to plug in other peoples trailers that I would sometimes pull. I still have the adapter ... it is VERY easy to make if you simply order the right ends you want and a short piece of 7 conductor, 12 gaube trailer wire. I KNOW that eTrailer has all these parts, so I won't bother linking to them now. I DO recommend using dialectric grease in ALL of your wiring connections on the trailer plugs and sockets. It probably wouldn't take you more then an hour to make it up with a pair of wire cutters and a screwdriver and the dialectric grease. You would have to use the diagrams that come with the connectors you buy to make sure that you connect the two ends properly, because the wiring layout on each IS slightly different, but still well marked.



Let us know what you decide to do.

 

[HBarlow]

Seafish,

I'm tempted to convert to 7 pin round on both ends then make up the adapter you mentioned but I have only recently installed two new seven blade connectors on my truck, one at the rear and another on the flatbed near the hitch, and the one on m trailer is still like new. I guess I won't get in a hurry but will eventually do that.

The hidden truth is our weather is excellent, spring and summer are on the way, and I have a new Goldwing that needs to be ridden. I"m itching to take some long trips. Two fellow 'wingers are coming over around noon today and the three of us are going to ride up to Palo Duro Canyon then to the Big Tex Steak House in Amarillo, the one that advertises the free 72 oz. steak if you can eat it all. I couldn't/wouldn't eat a 72 oz. steak in a full year but it will be fun to visit the place.

Thanks for your advice and assistance.