The problem I was having with my 96 OBS was the A/C was not as cold as I wanted it to be so what I did was go to Advance Auto parts( you can use any part store ) and picked up a heater valve for a 96 Jeep Cherokee. Plumbed it between the heater lines and splice into the vaccum hoses for the blend door. This way the heater only works on floor, mix, defrost, and vent. It stops flow to the heater core and loops it back to the block so no hot water is flowing to the heater core so the EVAP doesn't have to fight with the heater core for cold air. I'll post some pics up. But the cab is about 20 degrees colder!! Takes 15 min 4 hose clamps vaccum line and a vaccum tee. Makes a world of diffrence.:icon_ford: