I have a 1994 E320 Mercedes-Benz my ac is blowing hot air on the end of the driver side and passenger side and cool air in in the middle. what do I need to fix

There is a door between the heater core and the evaporator. That door is not closing. You can pull the passenger or driver side kick panels and look for the vacuum controller. I'll peak through the FSM and see if I can find the exact location.

__________________

77' 300D, "Cartman" SOLD @ 150K (didn't know what I had)
83' 300SD, "The Superdon" 325k+ @ 28mpg
95 E320 wagon, "Millennium Falcon" 231k+ @ 24 Mpg
95 E300D, "Sherley" 308k @ 33.69 Mpg, currently anticipating a head
99 Suzuki Intruder "Trudy" @ 45 mpg

In the meantime, shut the side vents .

__________________

77' 300D, "Cartman" SOLD @ 150K (didn't know what I had)
83' 300SD, "The Superdon" 325k+ @ 28mpg
95 E320 wagon, "Millennium Falcon" 231k+ @ 24 Mpg
95 E300D, "Sherley" 308k @ 33.69 Mpg, currently anticipating a head
99 Suzuki Intruder "Trudy" @ 45 mpg

If your model is like the W210 I owned, it may be one sign of low-refrigerant in the AC system.