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Anything that goes behind your Chinook, flat, trailer, toys.
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Re: setting up for a tandem trailer -

June 16th, 2017, 8:08 pm

I spent some time today wielding a large mill bastard file, a sledge and a 5' steel pike, and got a 2 x 2 (too short) ball mount to go in until it was stopped by the end weldment for the ball. It will also come out, an item of concern at the time. An extended mount is on it's way from Amazon, and will attach fully with a bit more cold smithing. I won't need to have a shop go at it. I picked up a 7 pin receptacle at NAPA.

I learned that a brake controller plug is likely to be found under the panel at the driver's left foot. I still do not know if will be required, or if the ford blue wire puts out a progressive voltage. One controller I saw, (maybe all of them?) have an inertial component for progressive application of the trailer brakes. Wow, I never realized...makes me recall inertial navigation system on submarines.

It continues, Roly

Re: setting up for a tandem trailer -

June 17th, 2017, 11:14 pm

Roly wrote:I spent some time today wielding a large mill bastard file, a sledge and a 5' steel pike...


Remind me never to cross you :lol:

Seriously though, good going! The original receiver rides again :)

****
I don't think the blue wire does anything special in terms of being "progressive" or anything. I'm pretty sure if you have the type of brakes that need a controller that you still have to have one. There are other types though (surge, for example). The surge brakes on my boat trailer basically work by the force of braking compressing the coupler (which has a master cylinder/fluid in it). The brakes are hydraulic disc (but surge also works on drum brakes). This is fairly common on boat trailers since electrics and salt/water don't mix all that well.

The more advanced way (more common on boats over ~5,000# trailer weight) is known as "electric over hydraulic" and uses the typical Prodigy or etc. brake controller in the cab to control the hydraulic brakes on the trailer. Not that you'd need or want that. I don't know if anyone uses surge brakes on a cargo trailer (would guess more electric, but not really sure).

One disadvantage of surge brakes is that their release mechanism is not strong. So, for example, if you brake hard (or continuously) at the beginning of a long downhill, the trailer brakes could stick on and heat up. There is no way to specifically disengage them - that happens when the coupler is no longer compressed up against the hitch/ball (which may not occur on a steep downhill). I haven't had this happen, but I start down big passes conservatively and use engine braking (works nicely on the Chinook as I can glide down 6% grades pretty well in 2nd gear). There is more specific control with a cab brake controller and electric brakes.

Re: setting up for a tandem trailer -

June 18th, 2017, 7:48 am

Roly wrote:If one includes the blue wire in a 7 pin receptacle, do you get electric brakes operable, or do you need to add a brake controller in the cab, too? Or preferably? If used, how does it connect in the cab? is there a plug under the dash, or must cable be run?

Yep, you must add a controller. I did some research this morning, and here's the deal:

As you already found out, under the dash on the left foot panel under the parking brake, Ford put a connector with four pins for a brake controller (not normally included in our RVs) to use:

  • ground
  • battery positive
  • brake foot pedal switch (input to controller)
  • blue wire to rear harness for trailer brakes (the output from your controller)

An aftermarket under-dash controller will plug into that connector (via an adapter) to get power, brake signal input, and an output path to the rear (the blue wire).

If you're using a proportional controller, then its voltage output to the blue wire will vary according to your deceleration intensity. Otherwise with other controller types, it's just full on/off 12v, perhaps delayed and cycled.

Some info on two of the most common brake controller types: https://www.etrailer.com/faq-brakecontroller.aspx

Re: setting up for a tandem trailer -

June 18th, 2017, 10:54 pm

You know what's annoying? That if you DO have a brake controller in the cab (say a Tekonsha Prodigy or the like), you can't use that for toad (towed car) braking. Nope, you have to have another system for toad braking (of which there are several types). Hmmph!

Re: setting up for a tandem trailer -

June 22nd, 2017, 4:17 pm

Ready to go now with an extended ball mount, 2-5/16 ball, 7 pin RV connector wired up, and a progressive controller + adapter cable on it's way.

I think the 6x12 tandem enclosed trailer would be my best fit for Chinook towing, in view of Blue's figuring on weights, tongue and gross. Keeping the gross weight under 5000#, with a trailer rated for 7000, I get more payload than with a 7x14 due to a lighter 6x12. My local trailer dealers seem to be out of what I want. Maybe I can find one in Oregon on my way back to California from Washington in a couple of weeks.

Roly

Re: setting up for a tandem trailer -

June 23rd, 2017, 1:26 am

Roly wrote:Ready to go now with an extended ball mount, 2-5/16 ball, 7 pin RV connector wired up, and a progressive controller + adapter cable on it's way.


Sounds like you're ready to go! My cargo trailer is also a 6' x 12' but it's a single axle so only around 3,000# GVWR (2" coupler). I will say it tows fantastically behind the Chinook. I never "forget" any trailer is back there (not sure how people do that?), but this comes close. That said, it can only carry around 1650# of cargo, so nothing like the tandem (it's around 1300# empty).

Roly wrote:I think the 6x12 tandem enclosed trailer would be my best fit for Chinook towing, in view of Blue's figuring on weights, tongue and gross. Keeping the gross weight under 5000#...


5,000# seems like a good number to me. First of all, I'm not sure the hitch is up for more (that could always be checked and/or beefed up though), second, 5-7% of tongue weight (on a tandem) with that number adds around 550# to the rear axle (330# of tongue weight) -- I wouldn't think most 21-ers would want to add much more than that given that we're fairly close most of the time to the rear axle weight rating. Not saying one couldn't go over 5,000#, but it's my working maximum.

Happy trailer shopping :)

Re: setting up for a tandem trailer -

September 4th, 2017, 5:21 pm

Hi. Since I initiated this thread I got it all worked out...Hitch and trailer electrical connector. I have a brake controller on hand and will buy a tandem trailer somewhere between Seattle and Sacramento, as I travel down I-5 in a week or two.

My only hangup now is how does one pry open the panel to the left of the driver's feet, to get at the factory brake controller connector that is hiding under there?

Thanks, Roly

Re: setting up for a tandem trailer -

September 5th, 2017, 9:07 pm

Are you referring to what I would call the "kick panel" that would be to the left of your left ankle-bone while driving? If so, you just basically pry it off. (Don't you just hate prying on plastic things waiting for them to break?!). I usually give a fairly short/sharp jerk. The aft edge is under a bit of rubber trim, and you may have to work around some carpeting, but I think this is how it will go (based on my removal of the same panel on the passenger side). No guarantees nothing will break, but it's actually surprising to me how infrequently these plastic things do break. I expect them to shatter every time.

If it's a different panel, which one is it and maybe we can still help.

Re: setting up for a tandem trailer -

September 6th, 2017, 6:01 pm

thanks. Will pry.

Re: setting up for a tandem trailer -

September 7th, 2017, 4:19 am

Roly wrote:Hi. Since I initiated this thread I got it all worked out...Hitch and trailer electrical connector. I have a brake controller on hand and will buy a tandem trailer somewhere between Seattle and Sacramento, as I travel down I-5 in a week or two.

My only hangup now is how does one pry open the panel to the left of the driver's feet, to get at the factory brake controller connector that is hiding under there?

Thanks, Roly


Roly FWIW, I have had good luck with Freeway Trailers which is along I-5 Just before Tacoma WA. My current utility trailer was purchased there new in 1995. Have purchased parts from them as well.
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