The first time I went to start the engine on my boat, after having it trucked to my harbour and it sat over the winter, I went to start the engine and there was nothing. No click, didn't turn over, just nothing. I called the previous owner and he said that happens and to find the bottle of contact cleaner in the chart table, separate the white connector in the wiring harness and spray it with contact cleaner. I'm guessing this is what is referred to as the "trailer connector". They are not very reliable. I sprayed, it worked and now I spray regularly.