Two plugs?

[frosti]

I apologize in advance for the newbie questions, but hey, I'm a newbie.

We are in the process of buying a vintage (aka old) 5th wheel. It's a 1972 Kayot. We really enjoy the vintage campers, having pulled a 1968 Aristocrat travel trailer for the last several years. So when this Kayot came up we decided to throw caution to the wind and buy it. The learning curve has been interesting, to say the least.

Thanks to this forum and others, we've closed our knowledge gap considerably. However, I'm a little bit stumped on the electrical hook up. The dealer sent me a picture of the electrical and there are two plugs coming from the trailer. One is the older 7 pin round style, and I'm assuming this is what I will use for towing. I'm planning to get an adapter from my 7 blade connector on the truck to the 7 pin on the trailer. But the other is a 4 pin connector. And I can't figure out why there would be two different plugs.

Anyone have any ideas?

[frosti]

We tore up the check and drove home without the camper. The End. 🙂

[CurtisFamily]

Well, let us know how it turns out...

[frosti]

Quick update to anybody who wants to know: It turns out the 4 wire plug was for an old camper to TV intercom system.

The longer version:
We figured out the 4 wire was for the intercom fairly early. We also figured out that the 7 blade to 7 round adapter was not going to cut it. The 7 pin that was on the trailer was about 2/3 the size of the adapter. We took a picture of the cord to the local Napa, and the two guys behind the counter had quite a chuckle as they told us they had never seen one like that. So we gave up and cut the cord off. Spent the remainder of the afternoon with the dealer's handyman testing wires to determine which wire went to which lights and wiring them to a new 7 blade plug. Amazingly, everything worked! The left taillight was a little dim, but pretty minor.

My wife went into the office to fill out paperwork while the handyman and I went to hook up and get the trailer leveled when hitched to the truck. Backed up, the hitch wouldn't engage. Repeated this a few times, and then took a closer look. The kingpin was about 3/4 of an inch shorter than all the other kinpins on the lot. So the collar at the bottom lined up with the jaws rather than sliding below. The handyman and I both realized that the two were incompatible right about the same time my wife came out with the completed paperwork. I thought the saleswoman was going to cry when the handyman told her she would have to rip up the check as the rig wasn't going anywhere that day.

[Water-Bug]

If the 4 pin is on the back of the 5er, it is to double tow another trailer. Is there a hitch receiver on the back of the 5er?

[frosti]

My truck only has a 7 pin, so I'm hoping that one is active. If not, I guess I'll be looking for a 4 pin adapter. But that would mean no trailer brakes. Eeek.

Either way, I should find out Friday. We're heading over for final inspection and if everything looks good we'll be hauling it home.

[fickman]

I guess the next step is to see if they're both active. lol

[frosti]

From what I can see the two plugs do not intersect. So having a 4 pin "lights only" and then a 7 pin full hookup makes sense in a way. Good to know I have options. Thanks!

[rseymour21]

X2 with Sar Tracker

[fickman]

I'll let somebody else come along and tweak my explanation, but the 4-pin is what most utility trailers use. It just sends a signal for blinkers, running lights, and brake lights basically. The 7-pin connection adds 12-volt power and braking.

Anybody who has a 7-pin plug on their truck and has rented a trailer from U-Haul now owns the 7 to 4 pin adapter. Thankfully I've saved myself $30 several times by always having my adapter in the console.

On previous TVs, I had a hitch receiver installed by a dealer who put the 7-pin plug by default. On another one, I negotiated for the dealer to add a hitch receiver and they farmed it out to U-Haul. U-Haul put a 4-pin plug on and I had to fight them to get the 7-pin added. Then I had to fight them to actually run the extra wire for the 12-volt.

One time I sold a popup to a family from Australia who was towing with an Isuzu Rodeo. U-Haul had installed their hitch. They had a 4-pin plug. I wanted to close the deal so I towed it to their house and showed them what adapter to buy.

Looks like you're just ready to use either connection. If you have a converter/inverter and a battery, the 4-pin won't charge the battery from the truck. Also, if you have a 3-way fridge, the 4-pin won't run the fridge on 12v through the truck.

[SAR_Tracker]

Give it the ability to be towed by 2 different vehicle setups?

Do the wires on either harness connect to each other at any point?

[100ton]

Just a guess, maybe it's a "make do" connection in case the TV doesn't have a 7 pin outlet.

Robert
Huntington Beach, California