front ac on 1999 Lincoln Town Car stretch limo

What is your question?

Rear ac works good. When the ac is turned on in the rear, the vents in front (driver's area) put out cold air. However, when they get cold in the back and turn off the switch, only warm/hot air blows out of the driver area vents. The front switch says it is on AC Max and 60degrees, but the compressor won't kick on and the driver's area is hot. (The back can be turned on and off with no problem, they are comfortable.) Anyone know how to fix this problem? Thanks