Rstrahan
Well-known member
There is a common issue with the Ford E-450 chassis and the dash air system. The failure occurs when the dash vents will not open, with both heat and air venting through the dash and the floor vents. The reason is that the system is vacuum-driven and the failure point is where the vacuum hose goes through the AC system on the passenger side. If you look at the vent on the far right side of the passenger side up under the dash, you will see that it is run through the AC system. Invariably, there is where it fails.
How to test: the vacuum line runs from the intake on top of the rear of the motor (red vacuum hose) up and across the front of the engine compartment, to the passenger side, changes to a black hose where it dives into the AC system. You can test by disconnecting the hose where it changes from red to black, at the top of the engine compartment, just behind the battery. It is in a notch. If vacuum is there, reconnect and move to the passenger side. The black hose comes through the AC with a grommet sealing it. The line connects to a fitting. Again with the engine running, see if you have vacuum. 99 times out of 100, there will not be vacuum.
The fix: take it to the dealer and get out your checkbook and spend hundreds to have the AC disassembled to replace this line. OR....take the red vacuum line, and relocate it into the driving compartment, reconnecting with the black line past the grommet. Get a grommet and appropriate connectors for the hoses. Drill a small hole, run the red line through the grommet. Connect the system hoses with the connectors, securing the hose up under the dash. Cost is a couple of hours of time and less than $20.
Now works.
There are YouTube videos out there np and can help you.
Hope this helps others with this chassis
How to test: the vacuum line runs from the intake on top of the rear of the motor (red vacuum hose) up and across the front of the engine compartment, to the passenger side, changes to a black hose where it dives into the AC system. You can test by disconnecting the hose where it changes from red to black, at the top of the engine compartment, just behind the battery. It is in a notch. If vacuum is there, reconnect and move to the passenger side. The black hose comes through the AC with a grommet sealing it. The line connects to a fitting. Again with the engine running, see if you have vacuum. 99 times out of 100, there will not be vacuum.
The fix: take it to the dealer and get out your checkbook and spend hundreds to have the AC disassembled to replace this line. OR....take the red vacuum line, and relocate it into the driving compartment, reconnecting with the black line past the grommet. Get a grommet and appropriate connectors for the hoses. Drill a small hole, run the red line through the grommet. Connect the system hoses with the connectors, securing the hose up under the dash. Cost is a couple of hours of time and less than $20.
Now works.
There are YouTube videos out there np and can help you.
Hope this helps others with this chassis
