tekonsha commander xp brake controller

[MIDNIGHT RIDER]

Did you ever figure out this problem (my trailer brakes are constantly going off and on with out pushing the brake pedal and I have disable my breakaway)? I think I am having the same problem but I am not using the same controller.

On many FORD trucks, stray pulses of current can back-feed through the cold side of the brake-light switch-wire --- the one you get the trailer-brake signal from.

Several trailer-electrical concerns market a ? diode ? that is housed in a neat metal bracket that attaches adjacent to the brake-pedal.

This diode is spliced into the brake-light wire AFTER the brake-controller signal wire, such that it does not allow stray current to back-feed to the brake-controller.

Many will notice the need for this device when the hazard-flashers, and sometimes the turn-signals will pulse the brakes on the trailer.

 

[MIDNIGHT RIDER]

One more bit of fatherly advice :

Probably the best piece of advice I could give anyone intending to ever plug a trailer pig-tail into their truck is to FIRST establish a trailer-electrical "junction box" with at least seven threaded screw terminals; Del City offers a pre-made one in a neat lidded plastic box.

Mount this junction box somewhere easily accessible and close to the rear of the truck.

Route all trailer electrical functions to these LABELED terminals; GROUND, L-TURN, R-TURN, BRAKES, MARKERS, REVERSE, and HOT.

Now, you can attach a whole battalion of various trailer-plugs, simply by dropping a ring-terminal over the appropriate threaded stud and securing it with the nut.

All future trouble-shooting can be started right at this junction box, easily deciding if the problem is on the truck or the trailer side of the system.

LABEL the studs and LABEL the wires; you will always know what is what.

 

[cardana24]

On many FORD trucks, stray pulses of current can back-feed through the cold side of the brake-light switch-wire --- the one you get the trailer-brake signal from.

Several trailer-electrical concerns market a ? diode ? that is housed in a neat metal bracket that attaches adjacent to the brake-pedal.

This diode is spliced into the brake-light wire AFTER the brake-controller signal wire, such that it does not allow stray current to back-feed to the brake-controller.

Many will notice the need for this device when the hazard-flashers, and sometimes the turn-signals will pulse the brakes on the trailer.

This is known as a pulse preventer right?

 

[RLDSL]

I recently completely rewired my 5th wheel with all new lights( LEDs all around and the best thing I ever did was taking that lousy consumer grade 7 flat pin connector setup and round filing it and replacing the entire system with commercial 7 pin round connector hookup same as a semi truck . No more having to fiddle with loose connections at the plugs every time I hook up even though plugs are brand new, no more hitting bumps and having all the lights go out or getting brake faults. I just get to back up plug in and go. No more fuss. And whats really funny is the good stuff actually costs less than the lesser quality RV stuff if you buy it at one of the big truck discount supply houses, When I was picking teh stuff up at the parts house, my friend there was telling me that I didnt' have a very original idea. It seems that there are lots of folks getting fed up with those things and have come to the same conclusion.

 

[MIDNIGHT RIDER]

This is known as a pulse preventer right?

I am fairly certain that is what it is called.

 

[chevytaHOE5674]

replacing the entire system with commercial 7 pin round connector hookup same as a semi truck .

I've thought about doing that but then every time you borrow/buy/rent a trailer you need to use some sort of adapter to get it back to the standard 7 pin spade connector. Also I have more trailer connectors both on trailers and vehicles than I can count on all my toes and fingers, so I would either need to buy a pallet of connectors or have adapters.

If only years ago the industry would have just went to a standard 7pin with round terminals instead of a 6 pin round, 4 pin flat, 7 pin flat, yada yada.

 

[MIDNIGHT RIDER]

At least in the area where I mostly roam, the 6-pin round is king, especially on goose-neck live-stock and flatbeds.

In all my many years of hauling, I have not as of yet backed under a trailer that had the cheapie 7-pin RV-type plug hanging from it; I know that may seem impossible to many of you.

 

[chevytaHOE5674]

I have 3 GN stock trailers, 3 GN flatbed's, a BP flatbed and all came with a 7pin RV plug. I do keep a 7pin to 6pin adapter around as some older trailers (have an old BP 2 horse trailer) still use them.

 

[franklin2]

As for the good old trusty metal six-pin plug, many many people, even trailer manufacturers and sales people, wire the standard six-pin plug WRONG.

In the outer circle of five pins, there is one marked "S", meaning, for some unknown reason, trailer-brake "supply"; this is where the brake wire should be connected.

Why they didn't label that pin "B" for "brakes" is beyond me.


The center "A" pin is for "auxilliary".

Some route an always-HOT through the "A" to charge the silly break-away battery.

If the trailer (or truck) is wrongly wired, having an always-HOT on either of the "S" pins and one or the other of the brake wires on an "A" pin, then you will get the effect that you are getting.

I don't know about it being right or wrong, but you will run across adapters wired both ways, and like I said, they make provisions for swapping these two wires around inside the adapters. I do not know what type of trailer uses the center pin as the brake supply, but apparently they are out there somewhere. I have personally seen this little 6 pin wiring snafu mess up several trailer setups, some were never figured out, they just kept buying different adapters till they happened to get on that worked(was wired correctly). They are out there, just look at the outside of it and it will usually tell you how it's wired. Sorry I am mostly repeating what I said in a earlier post.

 

[chevytaHOE5674]

My 7 pin to 6 pin adapter has a plug in it that can be reversed to change the center pins function.

 

[MIDNIGHT RIDER]

The original posters thread has sort of become a general "how to wire a trailer plug" lesson.

I hope he has already found the solution to his problem amongst all the knowledge already given.


As for trailer cord/plug dependability and longevity, one thing I hate to see is a goose-neck or fifth-wheel with the trailer cord un-ceremoniously draped over a tail-gate and plugged under the bumper where boat-trailers and lawn-mower trailers were meant to be plugged.

Besides wearing all the paint off the tail-gate and all the insulation off the wires, this scenario puts a lot of un-necessary strain on the plug itself.

Compound this strain/leverage with a big heavy adapter and it is no wonder lights blink with every bump in the road.


The plug for goose-necks and fifth-wheels should be within a foot of the hitch-point, even if it means hole-sawing through the bed.

 

[RLDSL]

I've thought about doing that but then every time you borrow/buy/rent a trailer you need to use some sort of adapter to get it back to the standard 7 pin spade connector. Also I have more trailer connectors both on trailers and vehicles than I can count on all my toes and fingers, so I would either need to buy a pallet of connectors or have adapters.

If only years ago the industry would have just went to a standard 7pin with round terminals instead of a 6 pin round, 4 pin flat, 7 pin flat, yada yada.

You can always wire up an adapter REAL easily, I still kept the old 7 flat and 6 round on my truck and have a 6 round to 4 and one to 5 adapters in the glove box so I can still hook up to anything ( my little 8 ft utility flat still has a 4 pin on it ), I just dont have the problems with my big stuff anymore

And on the 5er I went through with all new wires all new lights and soldered in the ground connections to a running wire all the way back to teh junction box on the trailer instead of grounding to the skin like the factory trailer lights . Thats another nightmare after a long time ( my 5er is an '84 King of teh Road) the screws get rusty and you loose ground after a while when they ground them all to the skin and that makes the lights all flaky too. Grounding them all to a running ground wire eliminates that problem for good

 

[racer30]

Well I found this thread to late to get in my 2 cents on the problem the poster had....But I will chime in on the plug and play wire harness. most Trucks that Havent been mauled by a ******* with a wire cutter are fine being used as designed. The Ford Trucks where first to use the complete plug and play Tow harness that worked correctly and or didn't need modified to work with off the shelf product. Other Truck brands had partial pre-wire tow harness that needed some work to wire up correctly. The standard 7Way Bargman plug has been used in the RV industry for more than 40 years. Pickup Trucks come factory wired for this because it is the plug used for that towing market. The 6 way has been used for horse trailers and light duty utility trailers with two different wire cofigurations for even longer than that. The heavy Truck market uses the 7 way round pin for there Trucks. mixing plugs from light duty and heavy duty only makes for headaches when barrowing , loaning or renting trailers or Trucks. I have never seen a plug and play system fail from the MFG. Only from some goof ball cutting and splicing a bunch of 4'' wires together under the dash before I got a chance to rewire it correctly. All the Major Truck brands Now have complete Tow systems with fuses and 7 way plugs. I have seen alot of Trucks wired for several plug types and agree there is no better way than using a 7 way conection box under the truck with the correct wire size and terminals. The diode under the dash in the brake light cold side wire is for keeping the controler from pulsing when driving with the hazards on with electronic controls. Just my 2 cents.....RV master Tech 28 yrs

 

[MIDNIGHT RIDER]

I will second what RLDSL said about GROUNDing lights and such.

For several years, I have not relied solely on screw-mount-point GROUNDing for lights or anything electric that I install.

I go ahead and use the "skin"-GROUNDing with extreme attention to detail as if it were going to be the only source of GROUND.

I also then route a dedicated GROUND wire, just like the HOT, catching the GROUND on everything in that circuit, and then routing to one of my many GROUND-bars/strips/studs.

This dedicated GROUND wire needs be the same or larger AWG as the HOT wire.

On such things as fog- and driving-lights, if a screw-GROUND terminal is not already provided within the lights housing, I will drill/tap for a GROUND screw.

Common halogen lights that use the H3-type bulbs are very problematic for losing GROUND, due to the poorly thought out method of bulb attachment, relying on simple contact of un-like metals held against each other by a weak spring clip; these often don't work right out of the box; I thread a GROUND-screw in these such that it catches the base of the bulb itself and they will then last almost forever.

I also put jumpers from one system to another, such that everything is not only sharing common chassis GROUND, but also sharing the network of dedicated wire GROUNDs.

Electricity follows the path of least resistance, so I try to give it as little chance of resistance as possible; if it loses it's GROUND at one point, it can simply move along the many paths to the next available GROUNDed point.

Like RLDSL said, if one will run dedicated GROUND wires, most lighting problems will go away.