Chinook RV

I see what Blue and others wrote..Maybe I missed answers to my questions. I apologize if that is so.

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?

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.)

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?

I intend to buy a 12 x 6 enclosed tandem cargo trailer to move household stuff.

Thanks, Roly

Roly wrote:I see what Blue and others wrote..Maybe I missed answers to my questions. I apologize if that is so.

Hi Roly,

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...

Okay, here we go. I originally had this on a large paper document that came with my camper van along with a big box of various connector pigtails. The first photo shows the "schnozzles" I was talking about. Brown is the basic four, and black is the extras for the seven way. IIRC, Chinook had not used the mating schnozzle, but just used the wires plus crimps (but I did this 3-1/2 years ago).

I think you can click to enlarge. The part I outlined in red particularly applies.
Here are two other excerpts from the same document. I think they may have something to do with the connectors up forward you could use for brake controller? (But I haven't really studied them.)

PS: You may already know this, but a couple of things particular to tandems. One is that you want to tow with them as level as possible. The other is that you often don't need the standard rule of thumb of 10% tongue weight, but can go with 5-7% instead. You will also notice the tires "scrub" a little bit on tight maneuvers/turns (not usually when driving, but when backing into a spot and things like that).

Thanks, Blue, for the reply.

My biggest obstacle now is the 2" receiver. It must have been damaged in the past. The underside of the opening seems to have been impacted just enough to raise the bottom lip, decreasing the vertical 2" dimension. This is not obvious by sight. I could probably pound a mount in, but won't.

Any replacement hitches made that will bolt on to our Chinooks? This looks like it might not be a generic hitch.

I could diminish the ball mount with an angle grinder, but that's probably not even legal.

I put a deposit on a trailer in Santa Rosa that is good for 7 days. I hope to get the hitch and electrical plug functional before then. Hadn't counted on the damaged receiver.

Thanks, Roly

I could see that happening. If/when I drag at all, it's on the bottom of the receiver (so far nothing but a bit of scraping, but I could imagine the right "whack" deforming it perhaps?). On the other hand, the end is usually doubled (the 2" ID tube is surrounded by a metal "cuff" so it would normally be pretty stiff. Is there any chance that it has been weakened by rust? Not saying it has, just thinking from both sides.

I would think that a welding shop (especially one that does hitch work) could repair it. I think it was "simply" a custom weld to begin with. The tubing can be bought, and then they work with it. For example, when I was looking at various tow bars (for a tow car) and how they fit with the character-building rear door/hitch arrangement, I stopped in to a welding shop with one because the hole was in the wrong place to enable it to reach the hole in the receiver. They said they could source the bar stock, then cut and re-weld/re-drill so it would fit and be at least as strong as original. I've also had hitches beefed up on other tow vehicles. Usually it's not as expensive as you might think (or as I might think anyway). While they are "in there," they could look over the whole thing and make sure there aren't any weak points. At least this is my belief (always wanted to be able to weld -- taking two pieces of metal, basically butt joining them, and they are stronger than original... seems like magic!)

I would imagine that ASAP Metal Fabricators, in Yakima, Washington, might have made the original assembly. They did a lot of the custom metal work on our Chinooks. They are still in business, but they tend to only want to send the whole shooting match, and they don't come cheap (not saying they should). So I'd be looking at repairing what you have. I just try to look for a "good" shop that does tidy work and seems to think about/understand the geometry and stresses.

If you did want to contact ASAP for any reason:
888-386-8189 or 509-453-9143
www.asapmetalfab.com
valerie@asapmetalfab.com

Whoa. There's an orange wire to the rear, that's a battery feed controlled via a relay by the ignition switch (acc / run) ?!

Hmm. Sounds perfect for an addon on-with-key rearview camera. Will have to look to see if it's really there on our cutaways.

Thanks for those schematics!

Kevin:

I can't speak to other years, but mine had those exact connectors at the rear frame rail. The only difference was that Chinook had tapped into the one for the Chinook's lighting (not my favorite thing - wish they had just used the normal Ford wiring).

Roly:

I can't remember if you have the manual step or the electric one, but I looked under my manual step at the hitch tube and it looks to me like the receiver tube (It's around 16" or so long) is a fairly standard section of receiver tubing, and could be cut out and a new one welded on without too much trouble (for a welder).

Here is a photo of how mine looks. A few notes: I took this photo a couple of months ago, and it was for another purpose, so it only shows part of the receiver tube. But the tube ends not far out of the photo on the right. It's welded to the rest of the "apparatus" that is frame/bumper/steps/etc. It also has the little tabs on it to hold safety chains (if I were having this re-made, I'd consider making those larger so they could accommodate hooks better - instead I have the quick links there, not that that's a bad way).

Also, the lighting looks strange because I deliberately edited the photo to lighten up the hitch receiver. The large flat area/thing above the receiver is the underside of the upper step (the manual lower step is flipped up onto the top of it and out of sight).
Along with holes for the safety chains, the passenger side tab includes an area for fastening on a trailer electrical connector inlet. I found it more convenient to have that off to the left and less tucked under/less low.

Interesting to see those pictures. Mine comes to about one inch from being flush with the top step. I put a cheap camera there temporarily to play with so I can watch if I'm going to contact the ground with varying departure angles. Excuse the filth .

Cool idea. I guess you'll know, when the camera is scraped off That's generally where I contact, if I'm going to (yeah, I try to go diagonal, but sometimes I can't or it's still not enough). So far the only consequence has been some scraping on the outer "rim" around the end of the receiver tube.

You know, I'm not sure our hitches aren't pretty much the same. I mean, I wonder if mine just looks further from the step because it's a kind of "airy" low angle shot.