E-450 Stuck on Defrost Mode

[Bordercollie]

I suddenly have cold air coming through defrost vents only, not through dash vents. Defective parts are buried behind firewall on engine side, not accessible without much complicated disassembly. A number of You Tube how-to videos show an easy "bypass" replacement of vacuum hose, check valve, etc., fix to restore normal AC vent control. Ignoring the problem allows loss of vacuum and affects proper engine operation.

I'm hoping that a local RV repair shop can do the easy bypass repair at a reasonably small cost.

[30sweeds]

If ac is always on defrost and not just under load,it might just be the red line broken or disconnected.Nice video! Wish I'd seen it before I fixed mine...

[jy]

Does anybody know what year the E450 chasssis went to electric heater controls?

[ron_dittmer]

Bordercollie wrote:
Here's just one of the "how to bypass" videos on You Tube.

https://www.youtube.com/watch?v=ddcZnubJJgc

Nice, simple, straight forward video! Well wishes with the project.

[Bordercollie]

Here's just one of the "how to bypass" videos on You Tube.

https://www.youtube.com/watch?v=ddcZnubJJgc

[ron_dittmer]

As I understand you Bordercollie, you want to run a second vacuum in the area that is very difficult to access. I have seen write-ups on this in the past, and I "Get That". Just MAKE SURE that is in-fact the area of failure. Like you say, you want to seal off the leak as not to mess up your engine emissions, performance, and fuel economy.

Please follow up on what you learn and your final solution.

I wonder if a new hose could be pulled through the difficult channels by taping it well to the end of the old hose, then carefully pull the old hose out and have the new hose follow along.

[T18skyguy]

If you can find a mechanic with a smoke machine, they can hook it up and the smoke will reveal the location of the leak. They can connect it to the hose on the brake booster or other places will work also. Or you can try the poor man's smoke machine.Blow smoke from a big ol cigar and have someone watch under the dash while you watch the engine compartment.

[Bordercollie]

The actuator is not the problem, it's a broken rubber vacuum line down behind the engine not easy to get to without a lot of disassembly, much easier to rig a bypass vacuum line per various You Tube videos.

[klutchdust]

On another Ford product my in laws had it required removing the dash pad for access to those actuators. Removing the dash is not as complex as it might seem , some screws and it can be tilted backward. However. I am not familiar with this application .

[Bordercollie]

Our rig has vacuum actuator, I moved it manually and cold air came out of dash vents.

[winnietrey]

In my case rats had chewed through the hose. Seemed like was $150 or so if memory serves. Did have a bit of trouble finding someone that had seen if before and knew how to fix it

[Bordercollie]

Pretty sure from all the videos that my 2004 Tioga E-450 has vacuum actuator. There is a small length of rubber hose that rots and breaks and a check valve that is buried behind the engine, behind firewall. At 83 I can't do DIY much crawling under dash, etc. This sounds like a common problem on older E-450's.
Ford should have made maintenance easier.

[theoldwizard1]

Older E-Series used vacuum actuators while the newer models used electric.

[bobndot]

You don’t need an rv shop $$.
Any mechanic that has van experience will work. You just need someone willing to work outside if your rig doesn't fit in the bay.

[theoldwizard1]

I agree with carrying. Usually all of the actuator are inside the cabin.