To make the autodimming compass RV mirror work, it needs ground, switched power, and reverse-light power. I chose to splice the instrument circuit (R/Y) because I consider this to be an instrument. Ford puts it on the Run-option circuit (W/Pu). The only place the reverse light circuit (Bk/Pk) comes into the cab in this old truck is forward of the e-brake pedal where it simply loops from the frame harness (C205) to the engine bay harness (C202), so I spliced it there (including another tap for a backup camera trigger). The 3 wires are screwed to the A-pillar & w/s lip.
IF THE IMAGE IS TOO SMALL, click it.

The dash cam is mostly hidden from the driver's view by the RV mirror. But it's placed so its lens is in the wiper area so it will work in the rain. It's powered by a USB adapter in the dash beside the radio - the same one that powers the BT adapter for the factory radio.

Owner caption May 2020 · Photo 91 of 121