My understanding is that the Towbar hitching and brake assembly comes from the US and the break-away safety wire feature has been removed because it is not legal for Australian registration. When I picked up my boat Phil showed me the gadget to insert for reversing when disconnected from the car and told me that I would need to check as to whether my Holden's 7 pin plug had been wired with power to the 7th pin for a reversing light. I checked this at home with my Voltage tester and there is power. However I have found that when I reverse with all the connections made the solenoid which I presume closes the brake system electronically when the car reverse light powers it does not always do that and I have to jump out and put in the key which on mine does not stay in place very easily. Any suggestions?
Secondly how do they check the functionality of the brakes under this system when you get the trailer tested annually? There does not appear to be any manual way of applying pressure on the brakes for testing purposes
Interested to whether anyone here in Oz has had this problem or can enlighten me.
I have the same setup - but still have the safety wire.
To test the reversing function, try reversing up a slight incline (Phil showed me how to do this in his driveway).
My copper brake pipe broke off at the end, and had to be replaced. I realised there was something wrong when everytime I slowed down, the trailer
would give me a bit of a push......
Berber Boy
I had terrible trouble with my US surge brakes. The solenoid generated a back EMF which created havoc in the electronic trailer hitch relay switches in the tow vehicle, so the brake release stopped working. The fix was fairly simple (well it was simple to the helpful people on this forum who told me how to solve the problem). A diode is installed across the solenoid to remove the back EMF voltage spike.
The surge brakes were good when they worked. Reversing up an incline or even on level ground will usually lock them up pretty tight if the release mechanism isn't operating.
A 1N4004, or similar diode will do fine, as it does not need to carry any significant current. You can find the topic that discussed Oskar's problem here:
