My compressor kicks on when heat is suppose to be on. Front blows cold air, back blows luke warm air. Very little pressure in the radiator hoses, showing about 120*, heater hoses about 95*.

 

The compressor isn't the problem. It's normal for the compressor to operate in many of the HVAC modes.

Check coolant level first, then try a new thermostat.

 

The compressor runs in all positions except vent and floor. If you have the electronic controls then the compressor runs any time you've set it to automatic.

 

Thanks for your replies, I have changed the therma stat, and made sure the fluid level was good. Still getting cold air from front and some warmth from rear

 

You could have the infamous broken blend door issue, or the heater cores could need a good flushing out. Are both heater core hoses hot, cool, or one hot and one cool?

 

None of the hoses are as warm as they should be. Top radiator hose is around 100*bottom was 75*. Heater hoses the about 10* different 100* and 90*. could the water pump be not pumping enough, The gauge shows below the half mark

 

That all sounds like the new t-stat is stuck open or is not sealed around it's edges.

 

Thanks I'll check that out tonite. Doesn't seem to be leaking though.

 

Replaced the therma stat again no change. Leaning to waster pump or fan clutch. Man at parrt store said that may be it. any ideas appreciated

 

If you can get a hold of a scan tool see what the coolant temp is. Or check the temp of the aluminum cross over with an infared thermometer. You should be running some where in the 190-200 degree range. If not them t-stat still not right or water pump not moving fluid. Could be blend door or plugged or air locked heater core. Just fought this on 2002 did a flush and a new t-stat fixed it

 

A water pump or fan clutch not working properly should not cool down the engine below spec, but overheat it. Not your case.
Your top radiator hose should be hotter then the bottom which you indicate it is.
Maybe a vacuum leak, not allowing the heater hoses to open properly?

 

(Unless I missed it), it would be helpful If we knew what year/make/model that is being discussed, but more than likely there is no heater control valve.

 

Is the engine overheating at all?

 

It's a 1998 Lincoln Navigator. and no the motor doesn't seem to be overheating. I'm using a lazer therm to get Temp, the only place I get anything over 150* is the maniflod

 

Have you tried taking the temperature after a good 10 mile drive down the highway yet?