electric brake controller issues

G'day,
Only when brakes are applied.

Have you picked up controller power on wrong side of brake pedal switch??

The blue wire , as said, will only have volts on it when the brake pedal is depressed, and if the controller is working properly.....and typically, it will be in the region of 8 to 10 volts, depending on how you have adjusted the controller..

Tour boy,
Just try disconnecting and then reconnecting the battery. Once or twice my old controller sat there showing something was happening. IE a code would come up. I found by disconnecting and reconnecting the battery it would come good.

Nothing to lose.

RA.

Hi Bundy,
There are some controlers which give an indication that the trailer brakes are connected, by way of an led light on the controller. - In order for that to be achieved, a supply is sent to the trailer plug.
Consequently, When checked with a Multimeter (high inpedance) this voltage will be seen as approx 12 volt. However if checked with a 'test lamp' (low inpedance) then no indication will be seen - apart from the led light on the controller..

Regards
Jim

G'day Dave
Despite what you might have read above, there are a few situations/comments which I think are important. This question has arisen before on forums re brake controllers.

If you check the trailer plug wire and find it has a voltage then it may be quite normal.
This is because the controller is a solid state switching device and IF you checked the wire with a multimeter (which has high impedance ) then the wire, if not supplying the trailer at the time, will have an accumulation of electrons at the wire and the multimeter will read it as a voltage level. Even if plugged into the brake magnets you may get a slight voltage reading.

This is normal, and does not constitute a fault.

If the wire is tested with a test light, small LED or similar indicating device, then you shouldn't see any lighting indication as there is NO current flow available in the circuit until the decelleration of the vehicle activates the pulse width controller of energy to the brakes.

So, if the mutlimeter says YES there is a voltage and if a little piddly test light says NO then all is well.

If there is any appreciable current flow in the circuit the brake magnets will be trying to activate the brakes and this will cause undue wear of the magnet bodies or actually apply the brake to some degree if the current is strong enough.

Therefore, you are really trying to determine if there is any flow of current or not and not a voltage level/reading. A detectable level of voltage via a multimeter DOES NOT mean a fault is present. A miiliamp flow test might be more suited to find out if any flow is happening.
Think of it as being on standby. Most electrical devices and sound amplifiers as well, all have what is called, quiesent current, designed into them. It means they are slightly doing something so they can instantly react, rather than suddenly jerked into action from a complete "switched off" which causes uncontrolled actions.

It is a matter similar to a meat inspector. He/she must know what is normal in order to decide if there is a problem or not. An understanding of the system is essential for this decision to be made. Plain YES or NO comments don't cut the mustard.

Thanks all for your help. I'll take the trailer for rego next week so ill see if it all works.