hello, we have the ford 5600, changed water pump, thermostat 160 degree, and sending unit, it has the push on spade type, well now the heat guage reads a lot higher almost to the red, however the water temp stays right at 160 degrees and shows no sign of overheating while in use, tried a different sending unit from a and I parts thru the ford dealer very little change, the little bit I understand is that the sending unit sends an electric signal to the cluster? fuel guage seems to work ok, can the cluster sometimes fail? I was also told if cluster is bad the fuel guage wouldn't work, any help would be appreciated .