Need help with temp gauge

[Scottterry79]

I have a 72 c10 with stock gauges but have a tbi 350 out of an 87 Silverado. I have replaced the sender with an 87 sender because the threads are smaller and the 72 sender won't fit in the head. I have put in a new gauge and still no worky. I can ground out the sender wire and gauge pegs, I have 12 volts on the other side of gauge and bottom pole is grounded to cluster. The needle always stays cold. It may move just a hair after warming up but it is barely noticeable, it moves so little. Is there a difference in the two year model senders?
Posted via Mobile Device