Prodigy P2 Brake Controller Mystery

[Tinkerbelle]

Hello All,

I just bought a Prodigy P2 Brake Controller and had it installed yesterday. Tried to pull the Park Liner today and the trailer brakes engage every time I plug the brake/lights up to the hitch receiver - even when I do not press the brake pedal.

But if I unplug the brake/lights the trailer will allow me to pull it.

Does anybody have a clue as to what is going on? If there is some wire that has been crossed can anyone tell me where to look and how to uncross it?

Many thanks,
Tinkerbelle

[gordon2]

Return to the installer. They did not do it right.

[John in Michigan]

The brake controller, when everything is wired correctly, provides power through its blue wire to activate the trailer brakes. That blue wire runs from the brake controller back to Pin 2 on the 7 pin connector at the tow vehicle hitch (and trailer side connector). Here is a link to more details at etrailer:

https://www.etrailer.com/question-41784.html

So one possibility is that the 7 pin connector isn't wired correctly. For example, if the tow vehicle charging wire (12 volt battery +) was incorrectly connected to Pin 2.

[gordon2]

Originally Posted by John in Michigan

...
So one possibility is that ..

In fact there are about 1,000 ways they could screw up the install. Unless it worked OK towing the trailer when they finished the job but does not now, then there is little doubt they made one of many possible mistakes. Go back and make them fix it.

[Raz]

Without touching the brake pedal, what does the readout on the controller say? Do you get a number or .C? If you get a number then they most likely miswired the brake switch line. Unplug the controller. Brakes off? If not, then the error is most likely with the plug wiring. In either case, things are not wired properly. Back it goes.

[Tinkerbelle]

Hi RAZ,

Thanks,

When plugged in the display is "C." (connected) and the trailer won't budge. If we unplug it then display says "N.C." (not connected) and I can pull it (albeit without any bakes).

Able to tow with someone else's truck that has a brake controller ... just not mine.

[Tinkerbelle]

Thanks, John, for the link. I will show it to the technician that installed it. I have heard that it is easy to get the wires mixed up ...I just want this fixed so I can get on the road soon.

The link looks helpful so I will forward it to the technician.

T.

[Raz]

Originally Posted by Tinkerbelle

Hi RAZ,

Thanks,

When plugged in the display is "C." (connected) and the trailer won't budge. If we unplug it then display says "N.C." (not connected) and I can pull it (albeit without any bakes).

Able to tow with someone else's truck that has a brake controller ... just not mine.

There is a plug at the back of the brake controller. It lets you disconnect the controller. Doing so would eliminate it as a cause of the problem. That's what I was suggesting you disconnect. That said, it doesn't sound like the controller is your problem. I would look at the 7 pin on the tow being miswired. Blue brake line swapped with the black charge line as John suggested. Take it back and let the folks that wired it fix it. Do let us know what they find.

[Joe Romas]

What kind of tow vehicle do you have and how much wiring did the technician have to do? Did it already have a 7 pin connector?

Joe

[gordon2]

Originally Posted by Tinkerbelle

..

Able to tow with someone else's truck that has a brake controller ... just not mine.

There is also the possibility that the brake controller itself is faulty even if wired properly. However this is very unlikely. In many years, I have only heard of one Tekonsha brake controller being bad and it was replaced as no charge. If you bought the controller from the same people who installed it then they are still responsible. If not then you might want to see if there is another trailer with 7 pin and elect brakes you could try.

[Tinkerbelle]

In response to questions, and thank you for the help/advice, the technician only installed The Prodigy P2. I can tow the trailer with someone else's truck that has a different brake controller. With that in mind I don't think it's the 7-pin cable that comes from the trailer but perhaps the 7 pin plug/outlet. And I wonder if my 4 pin is messed up as well. Going back to technician today. If he will tell me what happened I will report back but he may not want to say what he did wrong. As long as it is fuxed I dont care...just lost time and gasoline in getting things corrected so that I am safe on the roads.

[gordon2]

Originally Posted by Tinkerbelle

.. As long as it is fuxed I dont care....

Its already fuxed.. you want it fixed!
From FUBAR to Repair.. GL

[Raz]

Originally Posted by Tinkerbelle

In response to questions, and thank you for the help/advice, the technician only installed The Prodigy P2. I can tow the trailer with someone else's truck that has a different brake controller. With that in mind I don't think it's the 7-pin cable that comes from the trailer but perhaps the 7 pin plug/outlet. And I wonder if my 4 pin is messed up as well. Going back to technician today. If he will tell me what happened I will report back but he may not want to say what he did wrong. As long as it is fuxed I dont care...just lost time and gasoline in getting things corrected so that I am safe on the roads.

Part of the installation of a 7 pin connection is not only the brake line but the 12 volt charge line. The wiring can be very confusing because the connections are made on the back of the socket. And switching them would cause the brakes to be locked. The good news is that if that is the problem the fix is quick and very strait forward.

[Scamper Jim]

Wooooh, slow down there. The fact that the controller shows “n.c.” when not connected, and “c.” when connected, indicates that everything is hooked up correctly. As per the instructions, once the controller is installed, it has to be adjusted for the weight of the load it is pulling.

Since the tech did not have your trailer to adjust it with, out of an abundance of caution, he probably just turned the control knob all the way up to full force, which is designed to lock up the brakes, which is what is happening.

Turn the wheel on the top of the unit back towards you until the brakes release, and then a little more. You can then adjust the strength properly by towing the trailer at a low speed and applying the brakes. You are looking for the spot where the brakes assist in braking, but don’t lock up. This is all per the instructions. They are a wonderful thing when read and followed.

The controller has to be adjusted after being installed and again when towing different trailers with varying load weights. Tekonsha has their own videos on YouTube showing you how to do the adjustment. They are not produced, as many seem to be, by some redneck who has half his teeth and about as much for a brain and proceeds to demonstrate it by producing a video that shows he has no clue what he is doing, but does it anyway.

[gordon2]

Originally Posted by Scamper Jim

...The fact that the controller shows “n.c.” when not connected, and “c.” when connected, indicates that everything is hooked up correctly. ...
Since the tech did not have your trailer to adjust it with, out of an abundance of caution, he probably just turned the control knob all the way up to full force, which is designed to lock up the brakes, which is what is happening.
.....

Not right... the controller should not activate the brakes at all unless and until the brake pedal is pushed or the manual over-ride lever is used. The OP said the brakes come on when he ONLY connects the trailer.

Originally Posted by Tinkerbelle

.... the trailer brakes engage every time I plug the brake/lights up to the hitch receiver - even when I do not press the brake pedal. ...

Perhaps the mis-wiring is causing the controller to get a signal that the brake pedal switch is on all the time. The P2 and P3 do activate the trailer's brakes at a stop after a few seconds to hold the trailer (on inclines I presume) but only if the brake pedal switch is on. So it is very possible they mis-wired it so the controller always thinks the brake pedal is being pushed. Maybe they "cheated' and tapped into the brake lights wiring instead of the switch but actually tapped the wrong wire. That is another of a million ways they could and did screw it up.

Joe asked an important question that has yet to be answered:

Originally Posted by Joe Romas

What kind of tow vehicle do you have and how much wiring did the technician have to do? Did it already have a 7 pin connector?

Joe

With newer vehicles being so complicated electrically, it is possible that tapping into the brake pedal switch is causing a problem, perhaps activating the tug's brake light circuit all the time. I think this may have been the problem with the Subarus that led Scamp to start using the AuTowBrake which does not require tapping into the brake pedal switch.

So tell us about the tow vehicle...

[LCH in Montana]

Using a multimeter, check the status of pin #4 and pin #2 on the tow vehicle receptacle, pin #4 should be the 12VDC battery charging source from the tow vehicle and pin #2 12VDC supply from the brake controller to the trailer brakes.

If pin #2 shows a constant 12VDC, and the voltage on pin #4 shows 0 VDC initially and an increase in voltage when the brake pedal is pressed, the wires are switched.

[Tinkerbelle]

Scamper Jim, I tried adjusting the brakes by using the dial to no avail.

The technician checked every wire in the truck between the factory installed wiring and the hitch receiver. It turned out that the wiring harness sent from Tekonsha had 2 crossed wires: the 2 and the 4 connectors were reversed. Mystery solved.

Thanks everyone for the help.

And yes, Gordon2, there is a typo in my previous comment. Pardon me.

[gordon2]

Originally Posted by Tinkerbelle

... It turned out that the wiring harness sent from Tekonsha had 2 crossed wires: the 2 and the 4 connectors were reversed. Mystery solved.
...

Do you mean this, where it plugs into the controller?



Or were the wrong wires connected at the other end? If so was it into a pre-wired tow vehicle?

Perhaps mystery solved and maybe you don't know more than what they told you but I am very curious to know if Tekonsha is at fault.

[LCH in Montana]

A picture is worth a thousand words. My interest is piqued as well.

[Scamper Jim]

Well, so much for giving the benefit of the doubt to the tech, after hearing that excuse.

The assembly process for computer chips, wiring harnesses, and virtually all electronics items is highly automated with robots, cnc machines and jigs that’s it difficult to believe that two wires got switched in the process. If Teckonsha’s assembly and quality control process allowed for that to get out of the plant, they would have some serious production issues and would not be the industry leader for controls.

Count me skeptical, I’m not buying it. I think what he meant to say is that the Teck was at fault, not Teckonsha.