Odd thermoswitch problem

[lennyseleven]

I had a warped head caused by overheating caused by thermoswitch going bad/fan not turning on. I replaced the thermoswitch got the fans working replaced the head. Now it appears that the thermoswitch is again bad.

Fans not working unless I found that B/G wire going to thermoswitch. So what could cause this switch to go bad twice in a row? Could i have put the t-stat back together wrong somehow keeping coolant from getting to that sensor? That doesnt seem right tho

thanks
Nick