Hey CRUZ68,
I got my thermo switch from a local autoparts store its a hayden unit, I don't have the number, but its adjustable for the turn on temp. I set mine to turn on at 200*F, it then goes off automaticlly at 190*F.
I set it there because I have a 180 T-stat in the engine, so on cooler days if there is enough air flow through the rad, the fan doesn't even come on, same on the highway, once I am moving the engine cools down from the air flow, the fan shuts off and isn't needed so doesn't come on, if I stay over about 35mph.
There are adjustable thermo switchs available at Summit and Jegs, or your local autoparts store may have something, I know the parts guy, so I just looked through his stock, till I found one that I thought would work for me, and it did.