.I had the darndest time trying to figure out what each of the wires on the back of the guage was for. Purple and black wires specifically. I am no boat mechanic, so things didn’t make sense to me.
There are 4 wires on the back. Red, yellow with green stripe, purple, and black. To the layman, I’d think red and black would be positive and negative. But no, there is a red and black wire coming from the jackplate, with connectors attached. The red matched the red, but the yellow plugged into the black. These wires came with connectors already installed, so you just plug them into each other. That left me a black and purple.
Not wanting to fry the dang thing, I called parts, was originally told to contact TH Marine for the info. I called TH and no one knew anything about it, but they all seemed to know that the guage kit didn’t ship with instructions. They said they had to find someone to ask, as the tech person I spoke to had no clue.
I called BC parts again, and asked if they could ask one of their installers which colors were pos and neg. They called me back a few minutes later, thank you Mike, and informed me that the purple wire is positive and the black is negative.
An hour after that, I received a pdf install document for the guage from TH Marine. I will include the screenshot if I cannot attach the pdf file here.
