Turning off braking when using air brakes?

[Orangecrush]

I use the air brakes a LOT. I use them so I don't wear or over heat my brake pads coming down long hills.

A few weeks ago I spent 1100 dollars replacing the brake pads on my enclosed trailer. I've come to realize that using the air brakes activates the brakes on your trailer. My Newmar did not do that, is there any way to keep the electric brakes on my trailer working so when I physically hit the brakes, they work but not when I use the transmission/air brakes for the trailer?

Thoughts?

Mark

[KRedburn]

Maybe first verify your connections:

for Prodigy controller:

Black - 12V Power
White - Ground
Blue - Brake Controller Pin on 7-Way
Red - COLD Side of the Stop Light Switch (only gets hot when you brake pedal is pressed) **
** this is key. It must be connected to a circuit that is hot only when the brake pedal is used.


more info:

https://www.anythingtruck.com/instru...0885Manual.pdf

[FOURWHL]

Your brake controller goes off the brake light signal. So would need to make so that the exhaust/engine brake doesn't activate the lights.

And just to avoid confusion - your service brakes (the ones operated by the pedal) are air brakes. I'm assuming what you're referring to is the exhaust/engine brakes (while there's a distinction between those two they're often used interchangeably) which is operated with the dash switch.

[johndjmix]

You know i was meaning to post this issue also, very not good the trailer brakes come on with the engine brake.


Theres got to be a wire we can disconnect to stop the brake circuit from being activated by the engine brake? Programable in the ECU maybe?


Or, what i was thinking of doing...find the brake pedal switch and grab the wire that goes hot off it.


--John

[Shifty]

Talked to a freightliner tech about this about 3 years ago and he said the computer is programed to only put the brake lights on and not trailer brakes

[Orangecrush]

Originally Posted by FOURWHL

Your brake controller goes off the brake light signal. So would need to make so that the exhaust/engine brake doesn't activate the lights.

And just to avoid confusion - your service brakes (the ones operated by the pedal) are air brakes. I'm assuming what you're referring to is the exhaust/engine brakes (while there's a distinction between those two they're often used interchangeably) which is operated with the dash switch.

You are correct, I should have differentiated but for some reason, I always call them that.

Originally Posted by KRedburn

Maybe first verify your connections:

for Prodigy controller:

Black - 12V Power
White - Ground
Blue - Brake Controller Pin on 7-Way
Red - COLD Side of the Stop Light Switch (only gets hot when you brake pedal is pressed) **
** this is key. It must be connected to a circuit that is hot only when the brake pedal is used.


more info:

https://www.anythingtruck.com/instru...0885Manual.pdf

Thank you! Going to look into that.

Originally Posted by Shifty

Talked to a freightliner tech about this about 3 years ago and he said the computer is programed to only put the brake lights on and not trailer brakes

So just to clarify, when I use the exhaust brake, my RV AND trailer brake lights come on. Are you saying that though the TRAILER lights come on, the brakes are NOT being activated, just the TRAILER BRAKE LIGHTS??

Not trying to play semantics, trying to understand. If the brake lights are coming on but the brakes aren't being activated (while using engine exhaust braking), then I'm good. I just "assumed" (yeah, yeah, I know....lol) that if the trailer brake lights are coming on, then the trailer brakes are being activated.

Thanks,

Mark

[bambamdrw]

Don't forget to check your Emergency Flashers as well.

My DX3 2017 M2 106, the Engine Brake does not activate my Tail Lights so this does not apply my Trailer Brakes! The "FLASHERS" do apply trailer brakes
when those are activated. Pulsing is very annoying, so when I'm in Slow Traffic I turn the GAIN to ZERO on my Brake Controller.

When I flat tow my Jeep, I'm running AirForce One Brake Controller on My Jeep, so neither is an issue for Air Activated Brake Controllers. I've been looking for Air Actuated Brake Controller for my Trailer, this seems like it would solve that problem with a Propotional, none-electrical Braking system.

[FOURWHL]

Your trailer brakes are being activated by your electronic brake controller. Your electronic brake controller is likely getting its signal to start working from the RV brake light signal. You'd need to swap this to something other than the lights or disconnect the exhaust brakes from the lights.

Your trailer lights are a different wire and get their signal separately.

[hitchn2go]

Figured I would chime in because here is the way I always assumed it worked. (Will use the Prodigy P2 controller for this discussion):

There are 4 wires from the Prodigy P2 controller: black, white, blue and red. First two power and ground, blue to trailer brakes and red is from pedal.

The blue wire feeds your trailer brakes as documented in the thread. The red wire from the pedal cause the controller to set voltage on the blue wire when pedal is depressed. The controller’s signal strength indicator is directly telling you how much brake is being applied via ever increasing voltage level on the blue wire. (There is a direct relationship with controller’s strength meter and blue wire voltage and trailer brakes)

So, if you are running with engine brake on and the engine brake becomes applied, a quick look at the strength meter on the brake controller should tell you if the trailer brakes are being engaged (a signal on blue wire). If you have no indication on the brake controller’s strength meter, then there should not be any voltage on the blue wire and thus no brakes being applied at the trailer.

As mentioned, brake lights still work as normal since the are getting voltage via a separate circuit ( I.e. different pins). Recently, my brake controller blew a fuse and was dead. Turn signals and brake signals still worked on the trailer but controller was offline and trailer had no brakes.

I believe the red wire is only telling controller that the pedal is being depressed so it better start sending signal to blue wire to apply trailer brakes. But a quick test run with observing the controller’s strength meter should let you know if there is another signal being applied on the red wire during engine brake.

For a correct wiring configuration, I would be surprised if there were any signal on red wire during engine braking...but, always open to learning something new...

[KRedburn]

Originally Posted by hitchn2go

Figured I would chime in because here is the way I always assumed it worked. (Will use the Prodigy P2 controller for this discussion):

There are 4 wires from the Prodigy P2 controller: black, white, blue and red. First two power and ground, blue to trailer brakes and red is from pedal.

The blue wire feeds your trailer brakes as documented in the thread. The red wire from the pedal cause the controller to set voltage on the blue wire when pedal is depressed. The controller’s signal strength indicator is directly telling you how much brake is being applied via ever increasing voltage level on the blue wire. (There is a direct relationship with controller’s strength meter and blue wire voltage and trailer brakes)

So, if you are running with engine brake on and the engine brake becomes applied, a quick look at the strength meter on the brake controller should tell you if the trailer brakes are being engaged (a signal on blue wire). If you have no indication on the brake controller’s strength meter, then there should not be any voltage on the blue wire and thus no brakes being applied at the trailer.

As mentioned, brake lights still work as normal since the are getting voltage via a separate circuit ( I.e. different pins). Recently, my brake controller blew a fuse and was dead. Turn signals and brake signals still worked on the trailer but controller was offline and trailer had no brakes.

I believe the red wire is only telling controller that the pedal is being depressed so it better start sending signal to blue wire to apply trailer brakes. But a quick test run with observing the controller’s strength meter should let you know if there is another signal being applied on the red wire during engine brake.

For a correct wiring configuration, I would be surprised if there were any signal on red wire during engine braking...but, always open to learning something new...

Total agreement with your comment however in addition to the "brake" signal on the red wire the Prodigy has internal accelerometers which detect deceleration and generate a signal on the red wire.

From the instruction sheet:
Important Facts to Remember
1. Do not mount or activate RF generating items
(cell phones, two way radios) near (less than 12")
the brake control.
2. The Prodigy P2 employs an inertial sensor. It
senses deceleration and generates an output that is
based on deceleration, thus the term “Proportional
Braking”.
3. The Prodigy P2 will “HOLD” your trailer with
25% of power setting while you are at a standstill
with brake pedal applied for longer than 5 seconds.
4. The Prodigy P2 will brake proportionally in
reverse. It will apply the appropriate brake voltage
based on deceleration.
5. For Technical Assistance and Warranty
Information call: 1-888-785-5832 or

Once you have verified that the controller is connected properly it must be programmed properly base upon the combined vehicle load and configuration. Note: One programming is generally not universal even for the same trailer.

One should go through the calibration procedure every time one hooks up to trailer for the tow. Different cargo weight can alter your needed settings.

[Larry-NC]

Originally Posted by Orangecrush

So just to clarify, when I use the exhaust brake, my RV AND trailer brake lights come on. Are you saying that though the TRAILER lights come on, the brakes are NOT being activated, just the TRAILER BRAKE LIGHTS??

Not trying to play semantics, trying to understand. If the brake lights are coming on but the brakes aren't being activated (while using engine exhaust braking), then I'm good. I just "assumed" (yeah, yeah, I know....lol) that if the trailer brake lights are coming on, then the trailer brakes are being activated.

Thanks,

Mark

Wait a minute! Look at the picture of the 7-pin connector before you start jumping to incorrect conclusions!
Pin 2 controls the brakes. It is a proportional (analog) signal. The higher the voltage, the harder the brakes are applied.
Pins 5 and 6 controls the stop lights (similar to the old 4-wire connection). It is a two-state (digital) signal, either 0v or 12v.

The state of the trailer stop lights has nothing to do with the state of the trailer brakes. Don't believe anyone who tells you otherwise--even the mechanic.

[EDIT]
Had the pins wrong when first posted.

An afterthought: Are you really sure you want to do this? Braking the tow vehicle and not the trailer is begging for the trailer to switch ends? If the vehicles are not Absolutely Perfectly in line and you brake the tow vehicle, the trailer will try to get ahead of it. You may be on top of this 99% of the time, but there will be that one time, going down a mountain, or even simply slowing in traffic for a right turn on a rainy or slippery day, when you don't catch it in time.

Wanna see the dent in the side of my Tahoe when my kid borrowed it to bring another car home on a dolly (no brakes)? He towed 200 miles with out issue and was one mile from home when he had to make a right turn (90 degrees but must stay in right lane) in heavy rain. The towed vehicle continued going straight and jackknifed the Tahoe. The crank on the dolly hit the bumper which absorbed most of the damage, but the Tahoe got a dimple.

[Scrapper]

Originally Posted by Larry-NC

Wait a minute! Look at the picture of the 7-pin connector before you start jumping to incorrect conclusions!
Pin 6 controls the brakes. It is a proportional (analog) signal. The higher the voltage, the harder the brakes are applied.
Pin 2 controls the stop lights (similar to the old 4-wire connection). It is a two-state (digital) signal, either 0v or 12v.

The state of the trailer stop lights has nothing to do with the state of the trailer brakes. Don't believe anyone who tells you otherwise--even the mechanic.

[EDIT]
An afterthought: Are you really sure you want to do this? Braking the tow vehicle and not the trailer is begging for the trailer to switch ends? If the vehicles are not Absolutely Perfectly in line and you brake the tow vehicle, the trailer will try to get ahead of it. You may be on top of this 99% of the time, but there will be that one time, going down a mountain, or even simply slowing in traffic for a right turn on a rainy or slippery day, when you don't catch it in time.

Wanna see the dent in the side of my Tahoe when my kid borrowed it to bring another car home on a dolly (no brakes)? He towed 200 miles with out issue and was one mile from home when he had to make a right turn (90 degrees but must stay in right lane) in heavy rain. The towed vehicle continued going straight and jackknifed the Tahoe. The crank on the dolly hit the bumper which absorbed most of the damage, but the Tahoe got a dimple.

I believe you have messed up the description of which pin activates which function.


Per your picture,

Pin 2 activates the brake magnets.

Pin 5 is the left brake/stop/turn light.

Pin 6 is the right brake/stop/turn light.

[Larry-NC]

Originally Posted by Scrapper

I believe you have the description of which pin activates which function reversed.


Per your picture,

Pin 1 is the left brake/stop/turn light.

Pin 2 activates the brake magnets.

Pin 6 is the right brake/stop/turn light.

Thanks, fixed now.

[Scrapper]

Originally Posted by Larry-NC

Thanks, fixed now.

That's ok, hope you noticed I had pin 1 and 5 switched, I too, fixed that.

[hitchn2go]

Originally Posted by KRedburn

Total agreement with your comment however in addition to the "brake" signal on the red wire the Prodigy has internal accelerometers which detect deceleration and generate a signal on the red wire.

The only reason that I can see that the brake controller would need to put a signal ON the red wire would be if the driver used the thrumbswitch on the brake controller to activate trailer brakes only. There has to be a signal to light up brake lights for this scenario. In this case, from the brake controller you would have voltage on the blue wire to activate trailer brakes and voltage on red wire to activate brake lights.

It could be something more complex, but this seems like the simplest design to me...

[Larry-NC]

Originally Posted by Scrapper

That's ok, hope you noticed I had pin 1 and 5 switched, I too, fixed that.

Yes, I did notice.

[KRedburn]

Originally Posted by hitchn2go

The only reason that I can see that the brake controller would need to put a signal ON the red wire would be if the driver used the thrumbswitch on the brake controller to activate trailer brakes only. There has to be a signal to light up brake lights for this scenario. In this case, from the brake controller you would have voltage on the blue wire to activate trailer brakes and voltage on red wire to activate brake lights.

It could be something more complex, but this seems like the simplest design to me...

The trailer brake controller only controls the brake signal line on the 7 pin connector. The light controls are from vehicle connects to the lighting systems (right/left turn, flasher, marker, stop lights)

the Prodigy controllers have internal electronics that modify the vehicle stop signal via internal accelerometers. The accelerometers are configured via the adjusting of the sensitivity and boost adjustments on the controller.
If your controller is not properly setup (i.e. sensitivity and boost are set to max) then it very likely could be applying brake signal to the trailer when the jake brake is in use. the "braking" is being detected by the accelerometers in the controller and therefore applying voltage on the control line and thereby applying the trailer brake.

I believe that the brake lights do turn on when the jake brake applies. This is a DOT requirement for newer trucks.

So, if trailer brakes are wearing out quickly then most likely cause is a miswire or misconfiguration of the controller for the combination.

[KRedburn]

Just another thought:

Some drive with their left foot on the brake pedal. this works on a race track but not a very good idea on a highway.
If you move the pedal just enough to close the bake light switch without applying your vehicle brakes, then your Prodigy controller could be interpreting that as a "braking requirement".

Just a thought on possibility of wearing out your trailer brakes.

[hitchn2go]

Originally Posted by KRedburn

The trailer brake controller only controls the brake signal line on the 7 pin connector. The light controls are from vehicle connects to the lighting systems (right/left turn, flasher, marker, stop lights)

the Prodigy controllers have internal electronics that modify the vehicle stop signal via internal accelerometers. The accelerometers are configured via the adjusting of the sensitivity and boost adjustments on the controller.
If your controller is not properly setup (i.e. sensitivity and boost are set to max) then it very likely could be applying brake signal to the trailer when the jake brake is in use. the "braking" is being detected by the accelerometers in the controller and therefore applying voltage on the control line and thereby applying the trailer brake.

I believe that the brake lights do turn on when the jake brake applies. This is a DOT requirement for newer trucks.

So, if trailer brakes are wearing out quickly then most likely cause is a miswire or misconfiguration of the controller for the combination.

So, we should be noticing the break-metering-levels on the brake controller every time the engine brake is activated OR every time we let our foot up off of the gas pedal? (If the sensitivity for the accelerometer is misadjusted to be the most sensitive).

In reality, if I am using the engine brake I am trying to lower my speed before I apply the brakes anyway, so it would not seem like that would be more than normal number of braking cycles going on—at least enough to get abnormal break wear. But I suppose it could if you are constantly lifting off the pedal and activating engine break unnecessarily.

I will have to look for those indicators on the brake controller next time out tho...to be honest, I have not noticed that before...

[wwestman]

As far as I am aware, it is illegal to have you brake lights illuminate when your jake/engine/exhaust brake activates. The ONLY time your brake lights are supposed to come on is when you push down on the brake pedal. Anything else is incorrect and in violation of standards.