I have an 84 150 that had some major wiring issues which resulted in most of the interior harness and dash burn. I also have a 90 donor truck, which I have recently swapped the dash out of. I am installing a Speedway universal wiring harness, and my question has to do with the wiper and heater switches.

Can anyone give me a breakdown of the connections on the backs of these switches? While I have the Haynes manual, which tells you where the wires run, nothing tells me which terminal is, lets say the "hot" terminal on the switch.

I wanted to knock out the wiring first on my rebuild since it is my weakness. I just don't want to lose interest this early in the build. Thank you in advance for any info.

 

Ok, so I've pretty much found all dash connections, except the instrument cluster. I have seen some nice diagrams on here for the "C250 and the C251" connectors behind the instrument panel, but none are of a 1990 dash. The plugs are the same, but all colors and wire locations are different. Might be easier if I post this in a different section, but thought I'd try here first.