The outside air temperature should still have the same reading. The installed sending unit should not affect the temperature gauge.
It reads the oil pressure
In the gas tank
Defective fuel sending unit.
That thing is known as a fuel sending unit.
bad sending unit in tank, or short in wireing.
You probably have a faulty fuel gauge sending unit.
There is no such animal as a "tachometer sending unit." The tachometer circuit is spliced into the ignition circuit and reads the actual ignition signal used by the ignition module.
probably the sending unit. unfourtunatly the sending unit and fuel pump are made in one peice, so expect it to be expensive
need a fuel tank sending unit, or check the wires, but given the year its most likely the sending unit
Could be that the wrong size tires are installed, or that somewhere along the line, a different rear-end gear ratio was installed.
you need to replace the sending unit in the tank!
did some searching,and found that is could be the ambient outside temperature sensor