I needed a treat.

  • The TCM (Towing Command Module) on the left is effectively a simple design. It mainly consists of three relays.

    1. Small relay that activates when the ignition switch is turned on. This also completely isolate my system from the car electrics so as not to void any warranty.

    2. Heavy duty relay for the Brake Controller

    3. Heavy duty relay to control charging the boat battery from the car.

    The many wires are to connect the TCM to the (RM) Remote Module on the dashboard where I can operate and monitor the system.

    The RM is made of a small plastic box where all the switches, leds and the meter is enclosed. I decided to build a new one as the old blue case did not have the space needed for a couple of new switches.

    The various components are soldered and strategically mounted for ease of operation.

    Once completed, it is mounted on the dashboard and the wires hidden for a clean installation.

    Testing time.

    I switched on the ignition and the green led on the RM came on showing that the TCM had 12V power.

    Then I switched on the Brake Controller Relay and the Red led on the RM came on showing that the plug on the tow bar had 12V power.

    Last, I turned the charger replay on and smoke was pouring out of the RM box on the dashboard. Before, I could switch the system off, all the wires on the Volt/Amp meter burned.

    F..k  What the hell did I do wrong?

    Stupid, stupid, stupid. I accidentally connected the shunt on the red positive instead of the black negative circuit.

    The diagram clearly shows the shunt on the negative wire. No wonder when power was applied it burned the meter.

    I bought a dozen meters a while back from China at $1.50AUD free shipping. It cost me $30 per unit in Australia. So the damage was not expensive but more work for me to correct the problem

    After a long day, I decided that a meal at the local RSL was well earned. When I got there, the place was packed. I did not realised that it's buy one meal and get a second one free. That's not fair, I'm on my own and no one to benefit from a free meal. I had salmon and vegetables. When everyone left I needed a treat to calm my nerves from having burn the volt/amp meter so I treated myself with a peach desert.


    Back to finishing the job tomorrow.