Question: How does a under dash or trailer mounted brake controller work?
Answer: The brake controller is activated by the driver from his normal seating position when he brakes.
The brake controller is wired directly to the battery and directly to the brake lights. When the brake lights are activated, a contactor within the brake controller closes and allows current to flow directly to the brakes at a pre determined voltage.
The knob on the brake controller must be preset according to the trailers weight. Most trailers carry the same weight daily. Example, builders trailer, car carriers, pop tops, RV, etc
The more the trailer is loaded, just turn the knob to a higher voltage before you commence your trip. If weight is removed then turn the voltage down before you commence your trip.
Multi vehicles without brake controllers can tow trailers with trailer mounted brake controllers.
NO longer do you need multiple brake controllers in all vehicles to tow the same trailer.
Note: We recommend that a licensed repair facility install Brake Controllers. Some buyers return the unit claiming that it is not working. In most instances a blown diode is the cause of this unit not working. Crossed wires cause diodes to blow. There is no warranty claim in this instance.
You cannot use the electric brake light to power the trailer mounted electric brake controller.
Why? Because the light wiring is undersize and will cause voltage drop to your brake magnets and brake lights. 2.5mm cable is common and OK for brake lights but not OK for electric brakes. Your electric brakes will be underpowered and only operate 50% of their capacity as well as being dangerous.
A 4mm cable should be drawn from your battery to your trailer plug pin #5. You may be able to use this spare cable as an accessory when camping to run small 12v appliances on all vehicles.
