I have a 1993 Ford Ranger with the 3.0 v6, my temp gauge is staying on the cold side it rises to the N than drops again, and my heats cold.

So far I’ve super flushed the cooling system
changed the thermostat
changed the temp sensor
and the fan clutch

I ran the truck after removing the old fan clutch and fan and it reached operating temp but even with the new clutch it’s still running cold

can anyone give me any other ideas on what to try I’ll take any advise, thank you

 

Is it blowing cold or hot air through the heater?
And where does the gauge rest when the engine is "hot?"