Four prongs, six prongs, seven prongs, help?

[William L.]

Folks,

My husband and I are hoping to purchase our first camper this month, a 2002 13-foot Scamp, and planning to have U-Haul put the hitch and a brake controller on our 2001 Mercury Sable station wagon. Electric brakes were installed on the Scamp last year for a trip out west, and it has a round, six-pin connection. It was towed with a Subaru with a flat 4-prong and an adapter, if I understand this correctly.

When we pick the camper up in another state, we were planning to tow it home using the 4-prong with the adapter to the 6-pin to operate the tail lights and turn signals and then deal with hooking up the brakes later. U-haul says we will need both a 4-pin and a 7-pin on the tow vehicle.

1. Does this make sense? We want to do this in the most efficient and economical manner.

2. Can a 7-pin on the tow vehicle be made compatible with the current 6-prong on the Scamp?

2. Not wanting to spend more than necessary, should we wait to install the brake controller and perhaps do it ourselves if we find the brakes are needed with our Mercury, or would it be more efficient to have U-Haul do it at the same time?

3. Based upon a previous post, would an RV dealer be a better choice than U-haul even if the RV dealer's location is not as convenient? It probably depends on the individual doing the work at either location, right?

Mrs. Bill

[Paul from NWOnt]

When I went to pick up our Casita, I was having issues making the truck's 4 pin mate with the 7 pin on the Casita. I used the easiest solution at the time: I hacked off the 7 pin plug, and wired a 4 pin in it's place. When I got home, I wired both the 4 pin, and a 7 pin onto the trailer to eliminate the need for adapters. Now I can tow with either setup.

I found the 6 pin plugs to be a little more rare then the 7's.

p.s. This was the first mod I did on the rig, and it was done the very day I picked it up.

[Loren G. Hedahl]

Folks,

My husband and I are hoping to purchase our first camper this month, a 2002 13-foot Scamp, and planning to have U-Haul put the hitch and a brake controller on our 2001 Mercury Sable station wagon. Electric brakes were installed on the Scamp last year for a trip out west, and it has a round, six-pin connection. It was towed with a Subaru with a flat 4-prong and an adapter, if I understand this correctly.

When we pick the camper up in another state, we were planning to tow it home using the 4-prong with the adapter to the 6-pin to operate the tail lights and turn signals and then deal with hooking up the brakes later. U-haul says we will need both a 4-pin and a 7-pin on the tow vehicle.

1. Does this make sense? We want to do this in the most efficient and economical manner.

2. Can a 7-pin on the tow vehicle be made compatible with the current 6-prong on the Scamp?

2. Not wanting to spend more than necessary, should we wait to install the brake controller and perhaps do it ourselves if we find the brakes are needed with our Mercury, or would it be more efficient to have U-Haul do it at the same time?

3. Based upon a previous post, would an RV dealer be a better choice than U-haul even if the RV dealer's location is not as convenient? It probably depends on the individual doing the work at either location, right?

Mrs. Bill

From your original statement above, you were not specific at to what socket is presently installed on your Mercury.

Whatever the case, if I were making the decision, I would have a 7-pin plug socket installed on the Mercury before I left and have a 7-pin matching plug in my possession.

Then I would replace whatever plug was originally on the trailer with the 7-pin.

The extra pin is an inexpensive nicety should you like to add something such as back-up lights on the trailer.

I've got a friend who tows an Airstream that has an intercom set up with a microphone in the cabinet above each wheel well. He can hear anything unusual going on in the trailer, but this is mostly so he can check the tire noise for any bumps, lumps, tread separation, etc. on the run.

[WaltP]

Folks,

My husband and I are hoping to purchase our first camper this month, a 2002 13-foot Scamp, and planning to have U-Haul put the hitch and a brake controller on our 2001 Mercury Sable station wagon. Electric brakes were installed on the Scamp last year for a trip out west, and it has a round, six-pin connection. It was towed with a Subaru with a flat 4-prong and an adapter, if I understand this correctly.

When we pick the camper up in another state, we were planning to tow it home using the 4-prong with the adapter to the 6-pin to operate the tail lights and turn signals and then deal with hooking up the brakes later. U-haul says we will need both a 4-pin and a 7-pin on the tow vehicle.

1. Does this make sense? We want to do this in the most efficient and economical manner.

2. Can a 7-pin on the tow vehicle be made compatible with the current 6-prong on the Scamp?

2. Not wanting to spend more than necessary, should we wait to install the brake controller and perhaps do it ourselves if we find the brakes are needed with our Mercury, or would it be more efficient to have U-Haul do it at the same time?

3. Based upon a previous post, would an RV dealer be a better choice than U-haul even if the RV dealer's location is not as convenient? It probably depends on the individual doing the work at either location, right?

Mrs. Bill

I'll take a stab at this from my limited experience.
First - are you sure the connector on the Scamp is a 6-pin? I've not heard of such. The round 7- pin connector has 6 pins around the circumference and the seventh is a center post. I've known others describe those as 6-pin, not realizing the center post is a 7th pin.
Second - there is an inexpensive (about $10) adapter that converts the 7- pin on a TV to a flat 4. There may be a similar adapter that goes the other way and perhaps that's what the previous owner used. But I don't believe it's possible to operate both lights and brakes with only a 4-wire connection.
When I picked up my 13' Casita last year, I had only a flat 4 on my Subaru and could not connect to the round 7 on the trailer. The only solution available to me, was to tow it home (about 250 miles) with no electrical connection. With such a small trailer, it was no problem, but probably slightly illegal. I immediately had the flat 4 replaced with a 7-pin connector and all is fine. I also bought the adaptor because I have a small utility trailer with no brakes that uses a flat 4.
I'm hoping that with luck you'll find your situation will be the same as mine.
Regarding your UHaul dealer-I cannot think of any reason you would need need both 4 and 7 pin wiring harnesses on your TV; just the 7 pin and the adapter if you also have that need. If he doesn't know that I would not trust his experience. But that may just be some miscommunication.
And regarding brakes, most states require them on trailers over 1000 lbs.
I don't know if that helps any, but good luck. I hope you enjoy your little trailer as much as we have.

Walt

[Pete Dumbleton]

The following link shows 4, 5, 6 and 7 pin connectors in a variety of shapes -- Scamp has used the 6-pin round on many trailers to handle brakes and battery recharge

http://www.etrailer.com/c-tec.htm

The Flat-4 and the 7-pin Bargman/Pollock (with six flat pins and one, centered, round one) are the most commonly found, hence they are the two most recommended. Adapters to switch the primary four lighting wires are commonly available at Wally, auto, hardware and marine stores.

Yes, the wiring job will be a result of the employee, not necessarily the employer -- I have read of some bad experience with U-Haul, but have had only good work from them, however, they primarily work with the basic lighting wiring because their trailers have surge brakes and don't have a house battery to recharge.

By the time I got to 7-pin trailers, I was doing my own wiring.

[WaltP]

Thanks for the correction Pete. Good to see such good experience on this forum.
So for Mrs Bill, is there a 6 pin to 4 pin adapter like the one for 7 pin? Maybe that's what she'd need. Otherwise replacing the 6 pin with a 7 pin would be a fairly simple job.
Walt

[Bill F.]

2. Can a 7-pin on the tow vehicle be made compatible with the current 6-prong on the Scamp?

Mrs. Bill

There is an adapter that plugs into the tow vehicle 7- pin that accepts a round 6 pin from the trailer. Here in Canada they range from $8 to $25 each. Using an adapter like this would allow bringing the trailer home with lights working. If you install a brake controller and a 12vcharge line before you go the brakes will work, and you can charge the trailer battery while you drive. Installing a 7-pin plug on the trailer would not be necessary unless you need a spare circuit which could be used for back up lights or some other application.
There has been a lot of discussion about the merit of brakes on 13' trailers on this forum in the past, but bear in mind that almost any tow vehicle has brakes that were only designed to stop the vehicles weight. These little trailers add almost a ton to that number which can really increase stopping distance in an emergency stop. I'd install the controller before the pickup, and it makes a lot of sense to do the 12v line at the same time because the wires can be routed through from battery to hitch socket together(saves removing mats and trim twice-$$).
Find out what size hitch ball and get the right one first time. It will likely be either 1 7/8" or 2" diameter.
Bill

[Pete Dumbleton]

I believe pre-fire Scamp 13' all used 1 7/8" ball and post-fire all Scamps are 2". I'd go with a 1 7/8" mounted and a new 2" from Wally in the toolbox -- Take it back if not needed.

[William L.]

Thank you all, for posting your experience and suggestions! We have found an adapter for a TV 7-pin to round 6-pin, which is what the Scamp we are hoping to purchase has. Next question: the supplier has an adapter that uses the center pin for auxiliary and another that uses the center pin for electric brakes. Which one do we need?

The 13-foot Scamp we will be picking up in another state has electric brakes that were installed last year. Can it be assumed that they would be operated by the center pin?

Lorraine (Mrs. Bill)

[WaltP]

You haven't said much about the provenence ot the trailer, but couldn't you find that out from the current owner?

[Pete Dumbleton]

On the common 7-pin Bargman-Pollack connector, one of the six outer pins is designated for the brakes, NOT the center pin (which is for what ever...). It's generally a good idea to remain as standard as possible in the wiring for a number of reasons.