[VAC] Re: Variable resistor for brake controller?

["Harvey Barlow" <harveybarlow@xxxxxxxxxxxxx>]

Jim,

Your memory of the method of adjusting braking with the old K-H controllers
matched mine exactly ... until I actually bought and installed one of the
old-style K-H hydraulic-electric controllers recently.  I think I said as
much in a list discussion before I actually changed over to the K-H.

To my surprise, according to the instruction sheet that came in the box with
the controller and confirmed by actual operation, rotating the knob on the
end of the manual brake lever that protrudes from the front of the
controller doesn't modulate braking force, but increases or decreases the
rate of application so that trailer brakes can be adjusted to slightly lead
the truck brakes.  Braking force must be adjusted using a variable or fixed
dropping resistor.

I cannot swear that both our memories were not correct regarding the K-H
controllers we used many years ago.  My new K-H is a model 81740C which
could have been redesigned or modified from the original although it looks
identical to the one I used back in the '70s.

My present experience is that with a heavy A/S (31'er to 34'er) trailer
brakes work fine without a variable resistor.  But when I hook on to my
tandem axle 22' utility trailer with brakes on one axle only, particularly
when lightly loaded, trailer braking is excessive without a variable
resistor.  When I eventually get my '66 Safari back together I'm sure I will
need either a variable resistor or a fixed dropping resistor to change brake
settings when I change from a heavy to light trailer.

Harvey