Temp Gauge problem

[cali201]

Hi, new here. I have a '96 Explorer Sport, 5 speed manual. About 2 years ago the odometer died, the Ford dealer said part was no longer available and I had find one in a junk yard. I bought a speedo unit (they are one piece, self contained) off of ebay last year and put it in. Everything worked but the temp gauge went to H and the check gauge light came on, so I took it out and returned it to the seller assuming it was a bad gauge package. I then just keep my old unit but of course no miles were showing on the car, so hard to have warrenty work on things like tires, etc when you can not show how many miles you went. Sooooo I picked up another unit on ebay and just put it in and the same thing happened, the temp gauge goes to H and the check gauge light comes on. All other functions of the guage package work. I know I am not overheating, in fact my old gauge, even from when new always seem to read way to low, normally staying in the cold area.
What could cause these last two units to go right to H and stay there when the engine is fine, not over heating?

Thanks

 

[Peanut74]

I had the opposite problem when I replaced my thermostat housing. I replaced the two sending units in the housing thinking it was better to do it now than have it to do it later down the road. After I got it all put back together my temp gauge did not work. I did some reading on here and found out that the sending unit I put in did not match what the gauge was looking for. Went to the Ford dealer and got a new sending unit from them and everything works fine now. You might be having the same issue since you replaced the gauge cluster.