I have a 70 challenger. I am going through the wiring now. I have a two speed wiper motor and from some other pics I have seen I believe I have a 70 two speed switch. My question is- There are two wiring plugs that plug into it, a gray one with 2 wires and a black one with 4 wires. The gray one plugs onto switch nicely, the black one, no matter how I try to attach it, misses one connection. Seems to be wrong plug end. Does a wiring harness from a later year have the black plug configured differently? Someone switched some of the interior from later year I am finding out. I wondered if he changed harness also? could I have a 70 wiper set up with a 71? or up harness? Any help would be great!