Dash AC blows out of the defrost vents
the dash AC blows out of the defrost vents when engine is under a strain, such as climbing up a hill, etc. my motor home is a 2000 itasca suncruiser. the engine is a ford v10 i feel it is a vacuum...
Forum Discussion
23hotrodr wrote:
You should make sure there is a check valve installed between the vacuum reservoir and the port it is connected to on the engine. This will hold vacuum in the system when engine vacuum is low. You can purchase one at any parts store.
The vacuum line that goes to the vacuum servo on the HVAC box under the hood and controls the outside/inside air door at the passenger footwell is prone to cracks and pinholes. It is easily replaced. You definitely have a vacuum leak somewhere. Good luck.
The problem is, the Duct system has built in leaks at the Vacuum actuator/motors. So, when the Engine goes to zero vacuum, the inherent leaks in the system drain the Reservoir and the default is defrost. Having that check valve will not fix anything. Doug
