temp sending question.

OK Bruce, I dont know what you use to get it out with. It is too small of a hole for a 3/8 ratchet. Allen wrench doesnt work, torx bit dont work. I pulled the plug on the other side of the thermostat. will that hole work. The plug measures just a hair over 1/2" outside to outside the threads. I dont know if that would be a 1/2" or a 9/16" hole. I sent a pic of the spot. What do you think. Do you know what takes that plug out. I will get it. It is just about the same size as the one I pulled so I would say a 1/2" is what I need but what takes the plug out. Bill