[VAC] Re: Brake Control _ Newbie Question

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxx>]

1: the brake light switch is not going to survive long carrying the
brake current.

2: with no controller or series resistor the brakes will lock tight and
slide the trailer tires.

3. with the trailer tires locked you will loose direction control of the
trailer.

4. without a brake controller to moderate the trailer brakes and without
the brakes connected you are depending on the tow vehicle to stop the
entire combination. Adding 4000 pounds out back is going to drastically
overwork the tow vehicle brakes, leading to rapid wear, loss of control,
long stops, and possibly brake system failure from overheating.

You NEED a brake controller, short term and long term unless you are
willing to drive only 20 mph or slower, not in traffic, and only up
hill.

I've pulled heavy farm wagons without brakes with pickups and life
suddenly gets unreasonably exciting when you need to stop, and the truck
is on a bit of sand over pavement. A truck with brakes locked up has no
directional control so you are along for the ride, not controlling the
ride. I don't do that twice.

Put a brake controller in the Jeep, the Range Rover probably won't be
able to handle the load safely.

Now we get to discussion of brake controller type. There are several and
those discussions are all in Patterson's archives of this VAC list. The
cheapest trigger from the brake lights and increase braking current with
time. They do allow stopping, but not always with variations on the
theme and do tend to over do the trailer brakes on long down grades. The
next better use a pendulum to detect some braking (once the brake lights
are on) and control the trailer brake current according to the detected
braking effects. The best used to use pressure from the tow vehicle
hydraulic brake line to control the trailer brake current. Tow vehicle
makers have limited the addition of hydraulic "loads" to the dual brake
systems demanding the added sensor use very little brake fluid volume
and so these have been hard to find and use but did the best job in
proportioning brake control between the tow vehicle and the trailer.

Gerald J.