Truck will not warm up.
I have a 94 Yukon with a 6.5L and the enging will not warm up. Temp gauge only comes up to second line on gauge. Have changed the thermostat and the fitting that comes off the water jacket. Have also changed the fan clutch as old one was locked up and wouldnt release. also changed heater core. Anything i am missing or any ideas what could be wrong.:argh: