I just got a 2004 Motorhome Class C. It is a 2004 E450 V10. The defrost will only run and I took a peak at vacuum lines on top of dash and looks like a few colored lines are broken and not plugged into the vacuum manifold or whatever you call it. I just got a vacuum tester and some black hose. Where can I find a diagram of the setup for the vent controls to route properly?

 

Any photos of what you found under that top center access panel?

Typically off the electro-vacuum function control on the front of the dash there is a 12" or so vacuum harness, attaches to the switch itself then into a mating connector in the upper cavity. If anything in that short harness is broken it can be easily replaced. Lines running from the other side of harness connector would have to be individually spliced and sealed in order to restore control of your vent/floor/defrost system.

I can post a few photos if you'd find that helpful? For now here's a diagram from an earlier year that might be helpful:



This is from an '00 & '03 but close enough to help in this case I think. More photos follow:

 

yes I do have some pictures I'm trying to figure out how to post them I did buy some vacuum line from autozone however how do I seal them and yes your picture looks the same. there's a wline that comes off of the can on the left that hooks in to the junction but not sure where because that one was dangling. I bought a vacuum test kit and I was going to hook it up to that line to see how much pressure I have.

 

Your photos need to be stored or hosted by a site such as PhotoBucket---the one I use.

Without one of your photos I don't quite get your description. These following photos might be of some help:







If you need to splice a line use a tight fitting vacuum hose to slip over the rather stiff vinyl/PVC lines used. With the right size flexible hose it should be sealed. If not use shrink wrap over the spliced hose, extending a few inches past the new hose. Don't over heat the existing hoses as they don't like high heat.

Lemme know if you need something more!

 

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here are some pics, looks like these hoses are just pushed on.

 

The can on the left in your pic has a red hose leading into the junction, I am not sure what port to hook that into on my junction. That is where the vacuum pressure is coming from correct?

 

I only see one photo---not sure what else is there.

I think I understand your problem now! Looking at my photo of the junction block empty end you should see where it belongs in the block. Let me get a better shot of the block showing it better for you----hopefully that'll help.

Give me just a bit---have some chores to do!


J W

 

OK will work on it tomorrow. Thanks, will report back

 

Two more photos of the block from the Function Control to the air flow system. Note the small yellow outline identifies a key that properly aligns the individual hoses to their appropriate servos.



Other side:

 

Fixed, Thank you. The only issue I see now is when I switch to FLR it still blows out of defrost. However, all other settings are good.

 

Glad to help!

 

I am Back....
I have a 2005 V10 with ac vent problems. I had some broken Vacuum line at the access panel on the dash. I repaired them however when I hit 40MPh is goes to default defrost. I rechecked all the line and tested the main line at idle and getting normal vacuum pressure. What else should I check??

 

Is this new problem with the same vehicle in your first post of this thread?

 

Same vehicle new problem, actually I haven't road tested since I fixed last time

 

The lack of vacuum when the engine is loaded probably means your check valve is bad or you have a large leak past the check valve.