91 sunbird 2.0 temp gauge

I installed a new head about 2 weeks ago and have it running pretty good. I always worry about heat and put a portable temp gauge at the radiator spout and am reading about 160 most of the time. the problem I am having is that my temp gauge on the dash does not move. Can anyone help me out with this? I did put in another used sensor ( being cheap ). It was off a car that the gauge was working. Thanks George