Trailer Brakes

[Jason24]

I wired up a basic brake controller and I can confirm power to the controller, and output from the controller when the manual button is pressed and when the brake pedal is pressed, but the indicator light on the controller never comes on (should light green then attached to trailer and change to orange / red as braking power increases) and the brakes never engage on the trailer. How does the controller know when the trailer is connected is there a measurable voltage / resistance value I should be able to check coming from the trailer? Does the dark blue wire under the driver side go straight to the trailer connector for brakes or does it have a fuse or anything else inline before reaching the connector?

Thanks in advance for any assistance offered.

Jason

 

[Mooseman]

You should check the trailer wiring itself and the brakes to ensure that they are working properly. You can do that by hooking up a battery to the trailer and putting +12V to the brake wire. You should see a spark on contact. You could also jack up the wheels and spin the tires with the power to the brakes to ensure they work. If nothing happens, then check the wiring, including the ground wire. If all that checks out, could be the controller is wired wrong or something. Since this seems to be a load sensing controller, a multimeter might not work. Put a moderate load like a headlight on the ground and brake lead and apply the brake controller. It should light. If the light on the controller doesn't light, I don't know what to tell you. I have a basic controller too and the light works all the time no matter if there is a trailer hooked up or not.

 

[Jason24]

You should check the trailer wiring itself and the brakes to ensure that they are working properly. You can do that by hooking up a battery to the trailer and putting +12V to the brake wire. You should see a spark on contact. You could also jack up the wheels and spin the tires with the power to the brakes to ensure they work. If nothing happens, then check the wiring, including the ground wire. If all that checks out, could be the controller is wired wrong or something. Since this seems to be a load sensing controller, a multimeter might not work. Put a moderate load like a headlight on the ground and brake lead and apply the brake controller. It should light. If the light on the controller doesn't light, I don't know what to tell you. I have a basic controller too and the light works all the time no matter if there is a trailer hooked up or not.

I'll see what I can find out from the trailer side.
This is the controller I have.
Reese Towpower/Trailer Brake Controller (74377) | AutoZone.com

Side Question: Is there an isolator or battery rundown protection for the aux power on the trailer connector?

 

[The_Roadie]

Side Question: Is there an isolator or battery rundown protection for the aux power on the trailer connector?

There is nothing. Part of the justification for leaving the ring lug off the threaded stud on the front fuse block is that the proper protection relay should be installed by the user. With an ignition-on control signal You can run down the vehicle battery easily if you're not careful.

 

[s10rocket]

I know it's been a while since your posting but did you ever figure out why your light would not come on? I am having the same problem with 2 of them, one on a 02 Chevy 3500 and one on a 99 Dodge Ram 1500. Any suggestions?

 

[Jason24]

I know it's been a while since your posting but did you ever figure out why your light would not come on? I am having the same problem with 2 of them, one on a 02 Chevy 3500 and one on a 99 Dodge Ram 1500. Any suggestions?

Not really, it seemed to work fine with some trailers, but not others. Those same trailers that didn’t work with this controller did work on other rigs. If I remember correctly (it’s been a while) the problem had something to do with the unit’s ability to detect that a trailer was connected. I eventually just go a better controller and everything seemed fine.
Good Luck,