WORKS ON ALL 1994 - 2008 F250-F450 Gas Engines as well. In 1994-2008 HD and Superduty trucks, hot engine coolant is flowing through the heater core whenever the heat or Air Conditioning is turned on. The system does not differentiate between the two. This is fine when you are running your heater. However, running the Air Conditioner is a different story. When your AC is on, your cold air is not only flowing across the evaporator coil but it also flows past the heater coil which has hot engine coolant flowing through it. Even with the air flow diverted around the heater core, the heater is still emitting heat just like a radiator. This results in a very inefficient air conditioning system in these vehicles.
This DIESELSITE Air Conditioning Control Valve will automatically shut off coolant flow through the heater core when MAX AC selected. The result is a decrease in duct temperature by 10 degrees or more which will be felt through your vent openings into the cab. This gets COLD!
Install takes about 15 minutes and requires no special tools. Everything you need is included in the kit. Full detailed instructions including color pictures are included.