I think there is only one plug in connection into the blower but there is a ground wire with a loop that has to be attached to a grounded bolt, which I think is towards the passenger door. If that wire isn't grounded, the blower won't work. My 91 had a melted fuse seat for the 20 amp fuse labeled heater when I got it, so I ended up cutting the wire going into the fuse box and adding an inline fuse to the blower. It ended up that I had a bad blower motor resistor, which caused the fuse wire to overheat. When I re-installed the blower, I didn't get it grounded properly at first and thought I had a bigger problem. A test light showed me the no ground. Your problem might be that simple. Good luck!