no electric trailer brake signal

[ilovetrains]

My electric trailer brakes stopped working. It had worked before, but no more. I use the prodigy controller, have had it for about 18 months. It shows the trailer connected, and when you slide the manual brake enagagement, the trailer brakes work. All lights on truck and trailer work. However when you depress the brake pedal, the electronic trailer brakes do not work.



I used a voltage meter to confirm that the voltage to the wire going to the prodigy controller does not change, 0 volts all the time. Obviously power is getting there because you can manually engage the brakes.



I also checked each and every fuse, none were blown.



I recall hearing that all lighting controls actually go through a computer on these trucks.



Can anyone think of a way to fix this without taking it to the dealer?

 

[RMachida]

The Prodigy applies power to the trailer brakes in proportion to vehicle's deceleration. So if it doesn't do that, it is a problem with the Prodigy not the vehicle. I assume you were moving when you pressed on the brake pedal, pressing on it while stationary (no deceleration!) won't energize the trailer brakes.

 

[ilovetrains]

The Prodigy applies power to the trailer brakes in proportion to vehicle's deceleration. So if it doesn't do that, it is a problem with the Prodigy not the vehicle. I assume you were moving when you pressed on the brake pedal, pressing on it while stationary (no deceleration!) won't energize the trailer brakes.

But even if it stationary, there has to a signal from the truck to the prodigy controller (the red wire) that tells the controller the brakes have been activated, correct?



I tested that with a meter and there is no signal on that wire.

 

[RMachida]

But even if it stationary, there has to a signal from the truck to the prodigy controller (the red wire) that tells the controller the brakes have been activated, correct?



I tested that with a meter and there is no signal on that wire.

Yes, there needs to be 12v when the brakes are pressed at the red wire. Sorry, I didn't notice that the brakes worked in the past.

 

[jelag]

On my 04 and 05 trucks..... fuse 1, is the main fuse for the electric brakes... . there is a seperate fuse for the truck lights, and the trailer lights..... I can't tell by your post if you've checked this correctly.....



If you pin out the trialer connector on the back of the truck... . there should be 0 volts applied to the trailer brakes... and as you mechanically move the lever or press the brake pedal the voltage should increase up to battery voltage..... on some controllers as mentioned above... . you have to be moving if you press the brake pedal... but you should get some change when you move the lever mechanically... .



In addition... some brake controllers have a gain control... . if someone has turned down the gain control... . you might have an issue with this... . on one of our controllers the gain controls what the hand lever does... on another controller the hand lever functions full scale no matter where the gain control is set... . so if want full braking you can get it.....



Hope this helps... .

 

[Bob4x4]

Sounds like you should check the wire from the stoplight switch to the prodigy.



Bob

 

[klenger]

See the last page at http://www.klenger.net/dodge/7-pin-connector-installation/trailer-tow-wiring.pdf for a wiring details for the 2004 trucks. I think the 2005 is the same. You can get the 2005 wiring diagrams from http://www.dodge.com/bodybuilder/

 

[ilovetrains]

Thanks Klenger, that gives me some ideas. I thought there was no real wire, rather it ran through the ECM.



Jelag, note from above post I checked literally every fuse.

 

[Cattletrkr]

I used a voltage meter to confirm that the voltage to the wire going to the prodigy controller does not change, 0 volts all the time. Obviously power is getting there because you can manually engage the brakes.

Which wire? One of them should be hot all the time. The other one is:

the wire from the stoplight

Since the manual slide works, your hot line should be good.



It's been a while since I've had a problem with brakes so I might not be remembering correctly.

 

[SSalzer]

I have the same brake controller and had the same problem. It turned out that I had a blown 20 amp (I think) fuse. I think it was labled something like trailer lights or brakes..... something like that.

 

[Dieselnerd]

I've been through this whole scenario recently with my BrakeSmart problem (to be updated soon). On the 2005, fuse 24, 15 amps, is the fuse for the brake signal to the controller. If that circuit is working properly your stoplights will work when the brake pedal is depressed and the ignition is NOT ON. Page 8W-54-2 of the 2005 service manual shows that circuit. So, quick test for that circuit is to step on the brake with ignition off and brakelights should work. When the #24 fuse is blown, your brakelights only work with the ignition on.

 

[ilovetrains]

I've been through this whole scenario recently with my BrakeSmart problem (to be updated soon). On the 2005, fuse 24, 15 amps, is the fuse for the brake signal to the controller. If that circuit is working properly your stoplights will work when the brake pedal is depressed and the ignition is NOT ON. Page 8W-54-2 of the 2005 service manual shows that circuit. So, quick test for that circuit is to step on the brake with ignition off and brakelights should work. When the #24 fuse is blown, your brakelights only work with the ignition on.

THANK YOU, THANK YOU, THANK YOU Oo.



I just read this, ran outside and pulled 24. Sure enough, blown. It is labeled CHMSL, so of course did not think that could be related. I should have known that a 15 amp fuse was too much to have the stinking third light on a seperate circuit.

 

[Dieselnerd]

Glad I could help. My controller was blowing that fuse as well as the 30 amp fuse that gives 12 volts to the controller. Pretty recent event so I'm very familiar with the whole trailer wiring diagram.

 

[champspa]

recently went threw this, pulled a no 8 wire up on the goose were I could reach it easily then pulled no 12 wire to each of my brake axles. Soldered them to the no 8 and now have no problems.

 

[DieselFiend]

Thanks fellas, this post helped me resolve my controller problem. It was the #24 fuse blown