Aaron, By process of elimination you have done about all the checking you can do. By shorting the coolant temp switch tells me you are getting power from the voltage source and it's going to the intended source. The circuit is working. I would repIace the temp swt again, maby you got a bad one twice. I have had 2 bad switches out of ten that I bought bad on the get go. I just sent another one out that was stuck closed. Another thing you can do to test the temp switch. Let the car heat up and tap on the pipe next to the switch. If it's ready to switch and won't this will help. I will send you one to test if you want. John hervey www.specialTauto.com