Re: Dual Pro hitch
Those units are "potted" meaning the box the electronics in is filled with a plastic material so there is no way any repairs could have been made to it unless the issues dealt with external wiring. If anything other than that was wrong, the unit would have been replaced. These are not inherently troublesome components so they don't often fail but as I said, it is electronic and it can. If you've had multiple failures, I think you have some wiring issues and that the charger is not actually failing. My suggestion is to disconnect it from the batteries. Using a voltmeter, plug the unit in and measure the voltage across each pair of outputs. If you have 13 volts or more they work. If not, inspect the wiring from the terminal all the way back to the charger. Inspect carefully for broken wires. If a wire is broken, splice it and then recheck. Check the power cord as the plug and its wiring can also prevent the unit from working. I trust you have checked the fuses and fuse holders for corrosion in each of the outputs!!!!!!!
