E450 RV ac problems
 

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:

Attachment 200836

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

Attachment 200837

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:

Attachment 200833

Attachment 200834

Attachment 200835

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!

Attachment 200832[IMG]https://www.ford-trucks.com/forums/Attachment 200832[/IMG]

[IMG]https://www.ford-trucks.com/forums/Attachment 200832[/IMG]

https://www.ford-trucks.com/forums/%3Ca%20href=
https://www.ford-trucks.com/forums/<a href=

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.

Attachment 200830

Other side:

Attachment 200831

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.

AH, the check valve, that lil $4 beauty is under the damn air box outside at the vacuum canister, over the wheel well, leaving you 2 options, pay Ford $1700 to repair it, they remove the entire heat/air unit to access under it, or cut a hole in the wheel liner. Be careful not to cut anything important. LoL

Can I just put a check Valve coming off the main vacuum line in the dash access panel?

Need it between the engine and vac canister to correct the issue, the canister is what holds the controls until the engine is producing vacuum again.

The little white tabs in this pic coming off the red and black lines off the can are those check valves because mine does not have those?

Attachment 200693

FWIW I'm about to dig into replacing my washer fluid bottle and that requires battery and tray removal. By the time its all exposed I'm of the belief these fricking vacuum reservoirs, hoses and check valve will be exposed (or close) to it by then?

If so I'll post plenty of photos in hopes of helping those facing this same issue---it seems a bit common.

Yea my washer doesnt work either

Mine works just fine, making this a bit of a PITA. Its leaking between the filler neck and main tank, not sure it can be repaired properly.

Plus I've already purchased a new Ford tank so why not? :)

Might be willing to send you the old one---it should fit from '92 until at least 2003---PM me!

If you had check valves on your controls, they'd not function because they are 2 way, If you can get at it by pulling the battery and tray, make plenty of pictures, and possibly video of it, I'm needing to get at it one day.

Photos for sure----I'm hoping to not encounter problems with the battery tray bolts though. Having replaced that tray in another van where the long battery bolt with top clamp had broken off, no way to drill/tap that hole so it all had to come apart. My '03 has the lower mounted battery clamp and it's not seized up so this might be a somewhat easier project one day soon.

There is another post here detailing cutting an access hole in the right side inner fender to get at the vacuum reservoir: https://www.ford-trucks.com/forums/1...efrosters.html Post #7. Not my first choice but workable none the less.

I personally just installed a new generic check valve in the feed line heading to the reservoir from the manifold. No need to pull that stuff apart. The old valve isnt going to cause any problems unless its stick closed, which seems unlikely.

Where is that line, you don't see much of nothing in the engine housing of the 97 and up vans?

Drivers side, on the intake manifold, about half way. It crosses the top of the engine compartment heading over to the passengers side. They break all the friggin time. Usually a small red hard plastic line, though in some production years it was black.

Ahh this bears some investigating then----photos of that too if I can find mine!

I was wondering the same thing, once I figure out why I only get hot air, can I put a second check valve some place?

Thanks,

-Brian

help
 

Anyone got any pics of this apparently I must have found the wrong vacuum line because this didn't work.

The red line is in that black plastic protector at the back, the air intake is against it, there are many wires running through it crossing to the drivers side from the passenger side. I can see mine exiting that loom, it has a big rubber section connecting it to the black line that goes down to the vacuum canister below the AC unit, if you look back toward the plastic piece you will notice the red line.

Thanks
 

Yeah I had figured it out. It came all the way out. The check valve was not even connected to the reservoir. Going to do the reroute now as soon as I get that acdelco part that's been posted. ac delco #10403762 apparently it's a reservoir with built in check valves. It's a GM part but apparently others have used it.

Wow, I'm needing to get at it, I plan to tie the red line into the black one going into the cab down there in the passenger floor at the firewall, goes in through the plastic, then I'll T it into a vacuum canister under the dash, no holes to drill.

E450 Vacuum Leak
 

When the A/C only worked in defrost mode and after reading here on the forum about the expensive possibilities to have it fixed at the "shop",so I decided on trying the following :
Instead of trying to track down the problem source I purchased a new vac. canister from Ford for $32 and check valve for $8. Added to this was about 15 ft of 1/8" I.Dia vac. tubing plus 5 ft of 3/16" I.Dia.

Total material cost about $50.

Then mounted the vac. canister to the top of fuse box cover, and added the 5' length to it which was then fed along to the check valve. The vac.tube from the manifold was plugged into one of the two remaining check valve outlets, and lastly the 15 ft tubing length was added to the 2nd check valve outlet. Next I fed the 15 ft tubing across the top of the engine compartment then down to the rubber boot that the steering tube runs through. Once inside the cabin the tubing was fed over the top of where the "dog house" sits then forward into the compartment shown in the top of the dash. The original black tube was snipped leaving about 5" from the tubing connector that gathers all the other tubes together. With a 2" piece of heat shrink tubing I made the last connection with the end of the 15 ft and the 5" length coming out of multi tube harness.

Works like a dream, and could have been finished in less than 2-2.5 hours if I wasn't so cautious about "what the Hell" I was doing.

Any comments good or bad happily received.

Ron

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