altarocks

I have a 7k# TT. When I hooked up after getting my truck new in July I couldn't seem to adjust the trailer brakes. Tried cranking the gain, experimented with the increased aggressiveness setting, etc but nothing seemed to help. With TBC set at max I tested by manually squeezing the TBC at 20 mph and it took over 10 seconds to come to a stop.

RV dealer says the TT brakes are fine and adjusted properly and that the problem is with the truck. After hearing that I connected my TT to my previous vehicle (Jeep Commander) and found that I have the same lack of braking that I have on my F150. When the RV dealer set up the Commander 3 years ago I could crank the gain to almost throw me into the windshield using just the manual brake controller. For some reason now I can't get enough trailer braking with either the Ford or the Commander.

The RV dealer is blaming the truck and I have no doubt if I take it to my Ford dealer they'll say the truck works fine and blame the trailer. Since it's happening with both tow vehicles it seems pretty clear to me that there is likely a problem with the trailer brakes. The other day an opossum ran out in front of me - I jammed on the brakes and the truck skidded but not the trailer. Aside from being dangerous it's putting a lot of wear on my truck brakes.

I'd like to confirm for myself that the voltage being delivered is accurate. I understand the trailer needs to be connected. Do I just connect it then use a tester to pierce the trailer wiring downstream of the plug? What voltages should I see and how do they relate to gain setting? Will not moving affect the readings?

Nighthawk87

When you squeeze the TBC manually it only applies the trailers brakes. That is used to calm the trailer during sway situations, not to stop the trailer and the truck together.

When you set the gain your telling the truck how much to apply the brakes in concurrence with your trucks brake when you hit the brake pedal.

Ideally you see the gain such that when manually applied at 20 mph it locks the trailers tires, then set it .5 gain below that.Basically you want as much braking power as you can but not to lock the tires.

According to the manual on certain heavier trailers a max gain of 10 may never lock the tires but that is the max so your stuck with it.

altarocks

I'm aware of how to adjust the controller. Something has changed with my trailer braking from the time my RV dealer set it up on my Commander 3 years ago and now. I can't see any effect by increasing the gain with either the Commander or the F150. I'm asking for info on how to test the voltage output in the hope I can use the readings to prove to the RV dealer that the TBC is working properly.

Steve Osborne

so we are clear....is this a 09-14 or 15/16....you say new...so i'm going with a 16....the brake controller works totally different than say an aftermarket model...the effort works off time and pressure you apply..the harder you stop the more trailer brake is applied..but only if the effort is set to trailer brake adjustment...
when you setup did you set the brake effort ?...low/med/high.....low...gain will do nothing if trailer brakes need adjusting....and even high they may need to be adjusted..

altarocks

It's a 2016 Platinum with max tow. I've spent hours trying all effort settings. None of them nor the gain seem to increase the braking effect. RV dealer claims the trailer brakes are working and adjusted properly. Right now my effort is set to high and gain is 8.5. If I brake hard the truck will skid (as much as the ABS allows) but the TT doesn't. Truck is definitely doing most of the braking. I just want to get the TT to brake evenly with the truck.

N3UP

The only LOADED trailer I have ever been able to get to lock a wheel had electric over hydraulic disc brakes.

With electric drums, such as on a travel trailer, loaded, you may not get enough brake effort to lock a wheel.

altarocks

I'm not hung up on whether it can lock up, but the trailer needs enough braking to at least come close to the TV braking force. I repeat, when I bought the trailer and the dealer sold me a brake controller and rigged my Commander, if I cranked the gain and squeezed the lever at 20 mph it braked with enough force to throw me into my seat belt. Now it takes 10+ seconds to come to a stop using the same test on both the Commander and F150.

N3UP

Since the trailer shows the same lack of braking with 2 different tow vehicles, that tells me the problem is there.
I think your RV dealer is BSing you about the brakes then.

My old sunline camper has drop axles and the axles block access to the adjuster slot on the backing plates. The only way to adjust the brakes is to pull the drums.

They make self adjusting trailer drum brakes now, I would invest in a set the next time you do brakes on the trailer....

Norotso

My first step would be to check for power by isolating (jacking up) each side of trailer and then apply 12v to ensure each brake locks up the tire when you free spin it. Next I would also inspect the wiring to ensure there is good connection and no rust at the splices. Another thing would be to pull the drums and ensure the hardware is in good working condition, this includes proper adjustment behind the drum. The biggest problems I found in the past from customers was over greasing the bearings and having the pads saturated with grease making them useless.
How far/much you have to do is all depending on what you find in the process of diagnostic....

JJM

Set the gain to 10 and try again? Brake effort to the trailer depends on pedal input, in my experience.