Engine fan engages and stays on with A/C turned on

[JimmyDw8xb]

Good evening,
I took the truck into the shop for wheel seals and air conditioner work. When I picked it up last evening after the shop had closed, I fired her up and headed for the house about 5 miles away. from start to house, the engine fan on my cm 870 stayed on. When the mechanic and I discussed air conditioning when I dropped it off he said he would evacuate it and charge it.
This morning I started it with the heat control in the red, the fan stayed off. as soon as I set control in the blue and turned the blower motor on, the engine fan came on. the motor wasn!t
even warm yet. My thought is the engine fan coming on and staying on is related to whatever he did to the air conditioning system. If so, what is the problem? any suggestions are appreciated.

BTW.... The air is not cold as well.