what voltage required for electric brakes

Hello boboyd,
I am not familiar with the Hayman reece controller but on mine there are 2 voltage adjuster wheels.The main one is set about half way and the other one is used to fine tune the abruptness of the brakes.To test the brakes while stationary jack up one wheel of the caravan and get someone to apply the brakes,the wheel should be hard to turn if not locked up.good luck.
Wally

If you put your ear near the wheels of the trailer you should hear a humming sound. I think the brake controller works on a pulse width modulation scheme, so you may not get an accurate reading on a voltmeter set to DC.

Brake controllers apply a minimum holding voltage and then the voltage is variable up to around 13 volts.

The voltage increase is set by the deceleration rate of the tow vehicle, sitting stationary you might only be getting 3.6 volts ..... slowing slowly at 100 kp/h may produce 7.5 volts and slowing quickly may give you a voltage of 11.2 volts and slowing very rapidly may give you a voltage of 13 volts.

It's all to do with how much energy is needed to slow a given weight down to the desired speed, the faster the slow down rate the more energy required.

There are other factors and how a brake controller works but I don't want to do what a lot of others on this forum do ....... go into to much detail and confuse the person who asked the question.

You should be able to feel the vehicle speed being retarded when using the hand control only.

I suggest seeing you know little about brakes and controllers I would recommended taking it to a brake specialist.

Well Bob, you can measure 3.6V or even 12v at the brakes and still have them not working at all.
You see, for the magnet to work at all a current (Amps) has to pass through it. If you had a broken connection, the voltage is still there but no current can flow.

IMO, measuring voltages is very misleading when it comes to electric brakes.
Measure the Amps passing through each magnet ( a clamp on DC amp meter makes that job easy) and you know what's going on.

On my trailer brakes, full on, each magnet requires around 4 Amps. Less Amps, less magnet power, less braking effect. The controller adjusts all that.
Your brakes may have a different magnet but I hope you get the gist how it works.

Hi Bob,
Suggest you take the car and van to Puttingdave to check it out for you.
Dave

More than likely, the vans wiring will not be earthed to the vans chassis. The earth will be achieved through the earth pin on the vehicle, so it will be likely a bad earth to the 7 pin plug on the vehicle. It is possible for the controller to be faulty but check the earth on both ends of the vehicle and if that fails, check it again... Also check the wires coming back to the earth from the brakes and the vans earth pin wiring is tight.. check the positive wire to the grakes also. Earth, earth earth,,,,, It usually the problem. Michael