"Dan D." wrote in message
om...

I have a travel trailer with electric brakes.
They do work in reverse.
In fact they work so well in reverse that I have to turn them
off when backing as it becomes very difficult to back into my
home parking spot with them on.

Why is that, do you keep your foot on the brake when you back up?




Some electric controllers use a pendulum and they may not
work in reverse.
Other controllers simply are tapped into your brake lights.
When your brake lights are on the controller is applying braking
voltage to the trailer.



I have never seen a controller like this, can you provide a brand name?

I have seen three different types of controllers:

Long ago, you used to be able to get a little pad thingy that strapped over
the top of your brake pedal. When you stepped on the brake, you stepped on
this pad and it sensed how hard you were pressing on the brake pedal and
applied the trailer brakes accordingly. There was still a controller just
under the dash where you adjusted how much trailer brakes for how much pedal
pressure. I am not sure why these went away, but I can imagin it was
because brake pedals got smaller and they may have had interference
problems.

There are controllers that tap into the tow vehicles hydraulic brake system
and will sense the pressure in the hydraulic line. This would be ideal for
controlling the trailer brakes! Years ago, when cars had simple brake
systems, this type of controller was easy to install and no problems. Then
cars started having dual master cylinders. Then cars starting having front
disk and rear drum, and had proportioning valves. Then anti lock braking
was introduced. The bottom line is that you could be taking a big risk to
make any modifications to the brake system, and I have been told that it is
illegal to do so.

The most common controller is the pendulum type. It uses the pendulum to
sense the decelleration of the car, and if the brake lights are also on, it
applies the trailer brakes. Which of course increases the decelleration,
which increases the trailer brakes, which increases the decelleration,
etc....

I have never seen a system that simply applied the trailer brakes whenever
the stop light was on. First off, such a controller would only have one
setting. On a panic stop, you really want those trailer brakes to work to
their fullest extent. On the other hand, you sure don't want the trailer to
drag you to a quick stop just because you tapped the brakes slightly.

On the pendulum type, if you adjusted it incorrectly you could get the
results of what you describe. Crank the pendulum level so that it was
always on, then adjust the gain to get the desired level of braking. Like I
said above, you would only have the one setting, so you would not be getting
the full use of the brakes.

Most of the pendulum controllers have a two-color LED that provides status
and feedback. On mine, the LED is off when there is no connection to the
trailer. When the trailer is connected, but no brakes are applied, the led
is GREEN. Step on the brake and the led will change towards red based on
the pendulum setting. To properly adjust the unit, you start with the rig
on flat ground, at a stand still. With your foot on the brake, adjust the
LEVEL control until the LED just changes from GREEN to a dim red. Now, with
your foot very lightly on the brake, let the rig roll forward and adjust the
GAIN setting so that you can just barely detect the trailer brakes (usually
the squeek....). This is a good place to start. The pendulum level setting
is usually right on now, so any further adjustments are on the gain. Crank
it up if you like to feel the trailer holding you back on a normal stop.
Lower the gain if your trailer tends to drag you to a faster stop than you
wanted.

Rod McInnis