Roly wrote:I see what Blue and others wrote..Maybe I missed answers to my questions. I apologize if that is so.
I think most of your questions are originals (not that it would be a problem if they weren't).
I tow both a tandem (boat) trailer and a single axle cargo trailer (not at the same time of course
), so I'll see if I can answer any of them...
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?
Depending on the type of brakes you have, you may or may not need a controller in the cab; but my guess is you'll have the type that do need the controller (but I didn't want to say you ALWAYS do -- for example my boat trailer has hydraulic surge brakes, so no controller needed (but the blue wire is still used for a reverse lockout, so the brakes don't stay on when you are trying to reverse). However chances are you'll have electric brakes and so want a brake controller in the cab (Prodigy, etc.)
I'm not sure about any pre-wiring up in the cab, as up to now I've only used my surge brakes which don't use a controller in the cab - everything is out back. Even though I only use 5 pins and so could use a 5-way flat, I use the round 7-pin anyway as I prefer the way they function (the 5-pin are more like the four way flat style, but just with 5 pins).
Roly wrote:Can I cut off the flat 4 pin trailer receptacle, attach a 7 pin in it's place, and tap the other 1, 2, or 3 conductors upstream of the Ford connector? Would those insulation piercing squeeze tap things do? (They seem dubious to me somehow.)
Yes, that's basically what I did. In other words, I used the four wires that formerly terminated in the flat four (green/yellow/brown/white), plus added the others (well, just the one so far in my case). I mounted the fixed 7-pin receptacle to the bottom edge of the bumper just to the left (driver's side) of the step. (You may have a different type of bumper - I have the one that's like a flat chromed plate with curved edges.)
To back up a bit: Ford has two "schnozzles" that they supply back near the rear of the frame for trailer wiring. One is the basic four wires (tail/stop/left signal/right signal/ground), and the other has the other three wires that make up a 7-way (12v power, electric brake, reverse lights). Note that colors are not always standard on these things, although typical is as follows (from what I know anyway)
Brown = tail/marker
Yellow = left turn/stop
Green = right turn/stop
White = ground
Blue = electric brake
Black = 12 volt power (although not that much considering long skinny wire)
Purple = reverse lights
Okay but back to the Ford "schnozzles" (sort of periscope shaped connectors you can plug other connectors into, or just use the wires and make splices). Chinook cleverly (or maybe "cleverly") used those wires for the vehicle brake/turn/stop/marker lamps. That one had me scratching my head at first. And the wires are long and skinny. I never had a problem with the boat trailer as I had already converted it to LED lights when I got the Chinook. But when I first pulled the cargo trailer (which has something like 28 marker and other lights), I suddenly found I had no trailer lights or Ford taillights. Yep, I had blown the fuse (it's in the sub-panel Chinook put in that's by your left shin when driving, labeled "marker lights."
The "real" solution would be to run larger wires, and maybe to put the fuse back by the rear door vs. by the driver (would save around 40' of wire loss); but since these days most trailers have LED lights (and they are desirable for other reasons), I simply bought LED marker/tail/license plate lights for the cargo trailer and hence have had no more issues (because they draw so much less power).
So anyway, the first Ford schnozzle will already have the four way flat wires crimped onto it (take a close look at the crimps as they are not the modern-day best - I started over from that point vs. right at the four way flat connector), and the second one, as I remember it, is not used by Chinook already. They are both along the driver's side frame rail about two or three feet ahead of the rear of the Chinook. I have a Ford diagram of the trailer wiring connectors and if I can find it I will post it here.
I would never use those tap things (3M Scotch Lock or similar). So I think you are right to be suspicious of them. I find them to be trouble (always on a dark rainy night, natch). I would use crimp/butt connectors with the built in heat shrink (or alternatively regular ones with added heat shrink over them). A good crimp connection will stand up to vibration well.
Roly wrote:What size ball mount shaft goes in the 2" receiver? I have a 2" one that I've never used before, which will not go into the receiver, as both measure 2" with no clearance. The one I have is too short anyhow, but what gives, are they of different classes?
That's a new one on me. The typical ones I know of are either 1-1/4" (light duty, not what you'd want here), or 2". In fact the more typical problem is they are too loose in the receiver and clank around. I can't remember exactly, but there might be a larger size that's super heavy duty. But for Chinook stuff 2" is just right. E-trailer has a great selection of the longer ones we need (they call them "ball mounts" - I'd previously thought of them as "draw bars").
So let me see if I can find that Ford diagram...