Ford Repair: heating problem, upper radiator hose, heater selection

Question
It's my sisters 98 Taurus. I just flushed and replaced the antifreeze, and found the heater to be blowing only warm. I thought the system may have an air pocket, then I noticed the a c compresser engage for a short time. What can be causing this, a sticking relay maybe? Thanks for any help you can be. J.R. Engine is a 3.0

Answer
Hello and thanks for your question.
I'll try to help.........
First, where was the selector knob positioned? If it was in the defrost position, the AC compressor will cycle every once in a while. When checking for heater output temp., use the vent or heater selection.
Is there a temp. difference between the upper radiator hose and the heater core hoses? If so I would suggest that you might take a look at the thermostat. Most Fords run a 190*-195* Thermostat.
I hope this helps with your problem.
If there is anything more I can do, let me know.
Thanks,
Erik