Ford E series stuck in defrost mode

[wackerb]

My shop quoted 7 hours just to diagnose why the venting was stuck in defrost regardless of the setting on my 2006 E-350 EB50. It turns out this is a common problem because the 3" long hose connecting to the vacuum cannister deteriorates causing a vacuum leak. It is hidden requiring the removal of the evaporator, heating coil, dash, etc. I'd like to recommend a youtube video,

https://www.youtube.com/watch?v=HsChKs3Jbsw

. It shows how to fix it yourself in about 45 minutes. I figure it saved me about $1,000.

It bypasses the stock vacuum cannister and reuses the existing hose and check valve/tee. If you want you can get a new cannister and mount in an accessible place inside. I'm waiting to see if I really need it.

I have no affiliation with the youtube channel, just a very satisfied user.

[Steve C]

Redoval (a fellow member here) sells a kit to solve this issue. While there are certainly other ways to tackle this repair, it does seem convenient.

https://www.vantageoptics.com/shop/V...Kit-p219070618

[JWA]

Here's a link for this thread along with anyone else not yet familiar with this defroster mode default condition, I hope its still relevant and helpful, 'tis over on FTE: https://www.ford-trucks.com/forums/1...-controls.html

Redoval, Scott and Vantage Optics offering is great. I went another way but the kit is a good way to ease the path towards fixing this for a fair price.

HTH

[mgmetalworks]

Ha! How timely! I just had to do this yesterday to a van that had some critter damage that took out the vacuum line way back in an inaccessible spot.

Anyhow... I did essentially what is outlined in the previous posts. Skipped trying to access the hard to reach reservoir and just installed a new reservoir and new lines. It was pretty easy to use a piece of wire to fish a line through the firewall.

Btw...the van is a 2013 with 100k miles. The short line between the check valve and the original reservoir was cracked and near failure anyway so it was going to fail soon if it hadn't been for the squirrel that got in there. This is one of those things for the Eseries that you might as well do as a preventative measure if you happen to be motivated.

[Flux]

Had same issue and did the new reservoir trick. I have rear AC / heater and even though it would be blasting AC up front my kids in the back would have hot air blowing on them.



Lord thank you for the internet and crafty people making Youtube vids.

[posplayr]

I have watched both videos from Jungle Explorers who simply reroute existing parts

https://www.youtube.com/watch?v=HsChKs3Jbsw

The video from Vantageoptics describing the kit supplies a kit with a new reservoir.

https://youtu.be/8vlTidauI1c

First, my guess is that the reservoir helps when you have a low vacuum situation for example you have the engine floored and do not want to switch temp controls to the defrost mode as a result. So while the controls work without a reservoir at idle (i.e. max vacuum) as shown in the video, you could have a relatively immediate loss of temp control without the reservoir, With the reservoir, you will have a certain amount of time before the reservoir vacuum is expended.

However, unless I am mistaken, I do not see how the vacuum check valve/ "T" is remaining in the system with the Vantage Optics kit. Am I correct here?

The first video basically pulls the check valve and long value line out from the OE reservoir. This is the part where he says you have to finagle it out. This long line is then repurposed by putting the check valve inside the cab rather than inside the fender as originally.

In comparison, the Vantageoptics kit seems to completely abandon the check valve down by the OE reservoir including the length of the vacuum line that the first video repurposed (albeit it running in reverse).

On further analysis comparing
#1.) single port OE style vacuum source and the
#2.) two port accumulator style reservoir configuration (see the attached figure)

the two ports will take some time to pull down a value in the accumulator reservoir, whereas the OE will be relatively immediate even without the check valve.

The check valve in the OE configuration however maintains a vacuum in the reservoir when the engine is shut off. A similar repurpose of the check valve for the two-port accumulator is also possible giving a similar behavior as the OE.

It would seem that the best solution is to remove the OE vacuum "T" from the OE reservoir and reuse the OE hard vacuum line (as in the first video), but include a new reservoir under the dash. Whether you use an OE-style single port or a cheaper 2 port as in the Vantageoptics kit is probably irrelevant using the check valve.

It is probably better to minimize the rubber vacuum line under the hood for that purpose I would recommend (at least that is what I'm inclined to do) reusing the OE vacuum line attached to the OE check valve under the dash.

The various parts to choose from are listed below and all are available on amazon.

• Ford D7OZ-19A563-A - Valve - AIR CONDITIO
  
• Dorman 47995 Econoline OE (inner fender) replacement Reservoir.
  
• Dorman 47076 Vacuum Storage Canister Compatible with Select Models (apparently same as the VanatageOptics)

I have used this in the past and much prefer it to electrical tape (which gets gummy) when having to splice into a harness where you cant get shrink tubing over without cutting through the wire.

• 3M Temflex Rubber Splicing Tape 2155, 3/4 in x 22 ft, Black, General Purpose Self-Fusing Electrical Insulating Tape, 1 Roll

[wackerb]

Installing a new reservoir under the dash is trivial, but I thought I'd try without it to see what happened and save having to buy a new reservoir. So far in normal city driving with a few short hills, which we have plenty of in Hawaii, there has never been a reduction in the A/C/vent flow indicating a critical loss of vacuum. I've yet to try it on a 6mi 3,000 ft. climb nearby. I recommend trying it without to see if it is really needed. Another video shows mounting the Ford reservoir if you want to buy it or the kit version mentioned previously.

I was surprised at how short the inaccessible part of the hose was, probably only 10-12 inches. I didn't have to "finagle" at all. In the unlikely case that the messenger failed or the tee didn't pull out, it think it would be fairly easy to fish another line in.

The method in the video reuses all the parts. I happened to have a rubber cap to seal the open part of the tee, but the taping method is simple enough requiring no new parts.

The video did not say what to do with the grommet at the firewall. I couldn't pull it off the tube and actually cut a little bit off the grommet to make sure there was enough tubing to attach the messenger. That wasn't really necessary as the pull was pretty easy. The grommet actually has a sleeve inside which joins the two pieces of tubing. I removed that and the grommet slipped easily over the tubing and back into its original position. Even without the grommet, pushing one end of the tee back into the firewall opening would provide enough protection for the tubing.

Here's a foto of the stock reservoir connect tube.

[posplayr]

I'm being somewhat anal with these vacuum controls because my 2000 E-30 XLT needs the rear A/C unit debugged and the A/C guy I went to said he did not want to touch it.

So if you had not heard, my 1997 E-350 RB (bought new and 125K miles and spent most of its time in S Cal ) was involved in a collision and was totaled. I was able to keep the vehicle for parts and still got a healthy payout at close to the top of the market.

So I decided to do some exploratory surgery( in the interest of science ) to see where this reservoir is located. As you can see in the pictures it is actually very close to the firewall grommet you see from the interior, just on the other side of the firewall but located under the A/C unit completely inaccessible.

I tested the reservoir and it still holds a vacuum. As you can probably tell the 4" section of line they used is rather aged despite the much better condition of everything else. It barely holds on so when there is a vacuum it is probably sealed with no vacuum leak. But it was on borrowed time and would need replacing if the van was going to be on the road.

So my plan is to salvage this OE reservoir and put it and the check valve under the dash on the passage side according to option #1 in the previous post.

There are two mounting tabs for the reservoir that you can see in the Dorman part. The vertical tab has a screw holding it which is away from the engine and basically only accessible after cutting through 3 layers of sheet metal. The other side is horizontal and riveted.

I will have to make a small metal bracket but should be able to mount the reservoir high up under the dash to the same mounting bolt as the Vantage optics kit.

[posplayr]

Originally Posted by wackerb

Here's a foto of the stock reservoir connect tube.

Looks the same as the one I pulled from the 1997 E-350. It was barely holding on.


So the need for a reservoir is going to be entirely dependent on how much lead footing you do with the A/C on LOL.

[twanonpoint]

Thanks to everyone that put in their info and wisdom in this thread!

I am dealing with this exact issue on my 2012 E-350 and reading all this is a big help!

I even left my car at a mechanic for a few days and they had no idea what was going on. You guys rock