Coolant motor help

I have a 1991 V-6 corsica. Lot of money has been put into this car but I have one problem. My coolant (radiator) fan doesn`t come on. I have a new fan motor, two new coolant sensors, new relay, new fan motor electric connector, wiring is good,l fuses are good, new 195 thermostat (i`m changing to a 180 today). When I do the diagnostic check under the dash, the FAN COMES ON. But it will will not come on when the motor heats up, even past the 3/4 mark.
What I want to know is, how to hook up a toggle switch safely. I had one hooked up but it was getting hot to the touch and melting the wire. How do I hook it up to work with the relay?
Here`s the wires involved: The red wire (hot) with the 20 amp sealed fuse, the red/black wire that goes to the fan motor, the pink/black wire, and the green wire. Which one goes into the toggle and then where the wire hook to going out of the toggle? :banghead:

I would not advise that, but am at a loss here for additional help. Probably already know this but you need automotive wiring and dc rated switches, do not use wiriing/switches used on normal ac voltage. I am curious though, does the fan come on when a/c turned on? It is supposed to. Do you have any way to test actual temperature of engine? (a scan tool etc) I think there was another post similar to this not too long ago. I will look around and see if I can find anything else. I have a 91 GM service manual. Can fax or email diagrams possibly if that would help. Might be Monday though before I can do it as I do not have a working scanner here right now.

My A/C quit working last summer, worked great before that. Nothing happens when I turn A/C on. Clutch doesn`t engage and the fan doesn`t come on. In diagnostic mode, it comes on.
I put in a 180 thermostat which helps greatly, but still no fan. I checked and double checked everything this afternoon, and still....no go.
I don`t have any way to test the actual temp, but I did let it almost get to the redline on temp gage and it was almost boiling.

Forgot to mention one more thing, there is no pressure left in the A/C lines either. I`ve heard that maybe the pressure sensor might be bad, but I didn`t think it would keep the fan from coming on.