l have a 1999 chrysler, town & country.It has dual climate control the heat works fine on both, but when l turn on the a/c l only get cold air in the front,and warm almost hot air in the rear.Anybody know what is wrong with it ?

Sounds like the damper is not moving all the way from the hot side to the cold side. l do not know where the actuator motor is for the rear duct work, however l would guess that it is located some where on the passenger side under the dash. Make sure the actuator is operating correctly. If it is then u may have a problem with the condenser being clogged or ur R134 gas is low & one completely circulating through the whole system. However my guess would be a problem with the door not closing all the way from the hot side to the cold.

l would really consider to taking it to ice cold air dont take it to the dealer very expensive plus they will charge u to to have it diagnosted take it to ice cold air free diagnostics in just minutes and its cheaper ther to fix

l had a Ford van that used a separate coolant diverter to control coolant flow thru the rear heater core. The heater core is in the same enclosure as the rear evaporator. The air goes thru the evaporator (make the air cool) & then goes thru the heater core that has coolant flowing thru it (as a malfunction), so u get warm air.
In my case, the diverter was rotted out internally. You could also have a broken vacuum line to it.
In my case, the front always worked fine, & after l changed that rear coolant diverter, the rear air worked great again.
Diverter should be in engine compartment, follow vacuum lines & coolant hoses to find it.

blend air door on rear a/c not moving possible door motor locked up or linkage loose. you will have to remove right rear panel for access to a/c housing. good luck.