A/c Blower defaulting to the defrosters
#108
11-13-2016, 07:50 AM
Mountain Pass
My 2004 E-350 also has the dreaded issue with the AC switching to Defrost when going uphill.
Honestly as I'm in Germany I don't want to cut my fender or bypass the OEM PITA Vacuum tank.
I heard that with the 2002 and later models, it is possible to leave the AC lines connected to get to the vacuum reservoir (while it's still necessary to remove battery, battery tray and move the ac dryer thing away).
In my friend's workshop, we can do almost everything except evacuating and refilling the AC.
Can anyone confirm this?
And BTW great forum!! Keep up the nice work!
Honestly as I'm in Germany I don't want to cut my fender or bypass the OEM PITA Vacuum tank.
I heard that with the 2002 and later models, it is possible to leave the AC lines connected to get to the vacuum reservoir (while it's still necessary to remove battery, battery tray and move the ac dryer thing away).
In my friend's workshop, we can do almost everything except evacuating and refilling the AC.
Can anyone confirm this?
And BTW great forum!! Keep up the nice work!
#109
11-13-2016, 08:14 AM
I Cut the fender to replace the check valve and later on I had a tank leak so I had to bypass the original tank and add a new reservoir inside the passenger foot well.
If I were you, I'll track the vacuum line-it goes from the top of the intake, to the base of the windshield on the passenger side, to the hidden reservoir. Disconnect it and find a way to bring it inside ( I think I've seen people drilling a hole next to the dog house, passenger side). Put a new check valve and a new reservoir and connect it to the vacuum lines that go to the AC controls.
I discussed how I did mine here, but I bypassed by the reservoir since I already had the fender cut. VanKrishna: Operation K.I.S.S. - Page 9 - Expedition Portal
If I were you, I'll track the vacuum line-it goes from the top of the intake, to the base of the windshield on the passenger side, to the hidden reservoir. Disconnect it and find a way to bring it inside ( I think I've seen people drilling a hole next to the dog house, passenger side). Put a new check valve and a new reservoir and connect it to the vacuum lines that go to the AC controls.
I discussed how I did mine here, but I bypassed by the reservoir since I already had the fender cut. VanKrishna: Operation K.I.S.S. - Page 9 - Expedition Portal
#111
11-13-2016, 06:18 PM
Just locate the red vacuum line at the back of the engine, relocate it inside by going through the doghouse, link it into a canister, now cut the black line that comes in through the firewall on the passenger side, it comes from the canister outside that you are replacing, put it to the canister you installed, creating the loop inside, the factory stuff can be left disconnected.
#112
11-13-2016, 07:33 PM
Just locate the red vacuum line at the back of the engine, relocate it inside by going through the doghouse, link it into a canister, now cut the black line that comes in through the firewall on the passenger side, it comes from the canister outside that you are replacing, put it to the canister you installed, creating the loop inside, the factory stuff can be left disconnected.
https://www.ford-trucks.com/forums/1...-problems.html
#113
11-13-2016, 08:05 PM
#114
11-14-2016, 04:27 PM
Elder User
Wouldn't it be worthwhile to test the vacuum integrity of the system branches? I had the same trouble and went with everyone's advice to add a new reservoir and check valve only to see the same problem but slightly delayed as I drove up the hill. From the vacuum line connection block that resides under the panel found on the dash top. From here you have easy access to the red, yellow, blue and white lines. I could test for leaks with a hand vacuum pump. Discovered the rubber line that connected to the rear heater control valve was shredded. This was underneath the van chassis. A length of new hose and a coupler made the repair.
#116
02-07-2017, 11:18 AM
AC vacuum reservoir
This is for the E-series Vans that have this problem of the A/C blowers in the dash defaulting to the defrosters while accelerating, then coming back while going back to normal speed. There is not a lot of information as to what causes this or how to fix it. This is what I did after a lot of research and asking questions. I don't know when Ford did this. But they buried a vacuum tank and a small check valve that controls or feeds the heater/A/C control unit. My van is a 1997. The problem is from the mid 90's to around 2003 or 2004. The check valve and the vacuum tank location is between the inside heater core case and the evaporator case which is under the hood on the right side of the vehicle. According to Ford to replace these two units, you must remove both cases from the vehicle. To remove the inside heater core case and box unit, you have to remove the dash. The evaporator case can be removed after you discharge the A/C, the battery and battery tray and just about everything around the A/C evaporator case. Ford dealers gets about 15 to 17 hours labor to replace the HVAC check valve and the vacuum tank. Crazy, right? !!!!!. The other fix is bypass that whole system with another external check valve and vacuum tank. The problem here is getting the control vacuum lines up to the dash control unit and finding a place to put the vacuum tank
This was my fix after looking at my options. First I popped the cover on top of the dash which uncovered some of the HVAC vacuum lines. The black vacuum line at this location is the one that feeds the HVAC control head in the dash. I disconnected the line and capped it. I then went under the hood and found the black line that gets its vacuum from the engine. I disconnected that line and connected it to a hand held vacuum pump. I gave it a few pumps and could only draw a little vacuum that quickly disappeared. Vacuum Leak !!!??. I removed the lower right side dash panel and the steel reinforcement behind it to get a better look at the heater box that would have to come out if you were to follow Ford procedures. I thought to myself, there's no way I'm going to remove the dash to get this heater box out. Looking at the lower far right corner of the heater box you can see the black vacuum line going thru the firewall. But wait, it goes thru the plastic heater box case.
I then went under the hood to see if I could find the other end of this line coming into the engine compartment. At this time I took the Battery, the battery tray, the blower fan and the front right headlight unit out. To get the blower out, you have to remove the dryer/receiver bolts and pull the unit toward the front as far as possible. I then pulled away the wire harness from the evaporator case as much as possible. I took a mirror with a bright light and tried to get a look at under the evap case. Trying real hard you can see the check valve at this point, but there is no way you can get to it.
Here's the fix. Taking some careful measurement from a given point under the hood on top of the fender well and under the heater. Take the right front tire off and transfer those measurement to the underside of the wheel well. This will put you just about at the 12 O'clock position. I measured out a 5" long (front to back) and a 3" side to side rectangle. I took my wizzor and cut the panel out. Make sure you cut just as deep as to cut thru. You don't want to cut anything on the other side of the cut. Remove the panel and there they are !!!!! the check valve and the flat vacuum tank. The check valve is just push rubber connectors, but the vacuum tank is held in by a small screw.. I checked my vacuum tank and it held vacuum, so I didn't have to take it out. I checked the check valve and it didn't work. I took the old one to Autozone and matched it up with a Dorman check valve for $3.98. I connected the proper vacuum lines to the check valve and installed it back in it's hole.
I have duel batteries, so I switched over to battery 2 and started the vehicle. It worked as it should.
OK !! Now put the panel back in. can't weld it, too much heat. Take the little panel you cut out and weld two small flat flanges on the short sides. Drill some holes in the two flanges. Clean, prime and paint the flange, so it doesn't rust. Put a bead of body panel poly seal around the flange and the hole in the inner fender well. Then stick the panel up into place and using short self tapping screws, screw the panel in place. I then put another thin coating of body seal around the edge and smoothed it out with my finger tip. Final step was 3 or 4 coats of undercoating
Then I put everything back together. If for any reason I have problems with this again, I have a panel that I can open up and gain access. I hope this helps anyone that might have this problem. My 2 cents !! Good Luck
This was my fix after looking at my options. First I popped the cover on top of the dash which uncovered some of the HVAC vacuum lines. The black vacuum line at this location is the one that feeds the HVAC control head in the dash. I disconnected the line and capped it. I then went under the hood and found the black line that gets its vacuum from the engine. I disconnected that line and connected it to a hand held vacuum pump. I gave it a few pumps and could only draw a little vacuum that quickly disappeared. Vacuum Leak !!!??. I removed the lower right side dash panel and the steel reinforcement behind it to get a better look at the heater box that would have to come out if you were to follow Ford procedures. I thought to myself, there's no way I'm going to remove the dash to get this heater box out. Looking at the lower far right corner of the heater box you can see the black vacuum line going thru the firewall. But wait, it goes thru the plastic heater box case.
I then went under the hood to see if I could find the other end of this line coming into the engine compartment. At this time I took the Battery, the battery tray, the blower fan and the front right headlight unit out. To get the blower out, you have to remove the dryer/receiver bolts and pull the unit toward the front as far as possible. I then pulled away the wire harness from the evaporator case as much as possible. I took a mirror with a bright light and tried to get a look at under the evap case. Trying real hard you can see the check valve at this point, but there is no way you can get to it.
Here's the fix. Taking some careful measurement from a given point under the hood on top of the fender well and under the heater. Take the right front tire off and transfer those measurement to the underside of the wheel well. This will put you just about at the 12 O'clock position. I measured out a 5" long (front to back) and a 3" side to side rectangle. I took my wizzor and cut the panel out. Make sure you cut just as deep as to cut thru. You don't want to cut anything on the other side of the cut. Remove the panel and there they are !!!!! the check valve and the flat vacuum tank. The check valve is just push rubber connectors, but the vacuum tank is held in by a small screw.. I checked my vacuum tank and it held vacuum, so I didn't have to take it out. I checked the check valve and it didn't work. I took the old one to Autozone and matched it up with a Dorman check valve for $3.98. I connected the proper vacuum lines to the check valve and installed it back in it's hole.
I have duel batteries, so I switched over to battery 2 and started the vehicle. It worked as it should.
OK !! Now put the panel back in. can't weld it, too much heat. Take the little panel you cut out and weld two small flat flanges on the short sides. Drill some holes in the two flanges. Clean, prime and paint the flange, so it doesn't rust. Put a bead of body panel poly seal around the flange and the hole in the inner fender well. Then stick the panel up into place and using short self tapping screws, screw the panel in place. I then put another thin coating of body seal around the edge and smoothed it out with my finger tip. Final step was 3 or 4 coats of undercoating
Then I put everything back together. If for any reason I have problems with this again, I have a panel that I can open up and gain access. I hope this helps anyone that might have this problem. My 2 cents !! Good Luck
#117
08-26-2017, 05:50 PM
I've had similar issues with a 1997 e250.
With all the posts I've seen, I think its just this side of criminal to not have included an access panel in the wheel well.
I spent some quality time with 2 vans at a pick n pull. Got 2 sets of hoses from the air intake area through to the dashboard switch. Considering that it took collectively 8 to 10 hours to get 2 complete sets, and a vac reservoir, the stated time by ford to replace the reservoir / hose is valid.
Discovered that with care, you can pull the check valve to the firewall and a bit through. In both cases, whether the short stub was still connected to the reservoir, it disconnected easily. In my humble opinion, entirely too easily. Considering the type of neoprene hose, and the lack of resistance, I'm inclined to believe that this is a planned obsolescence issue. Considering the hose type from the vac source to the first coupler, Ford obviously has many options.
I discovered a chewed connector at the access panel, and a failure at the reservoir.
Used the parts from PnP to replace all the dashboard lines. Used tape and stranded wire to carefully pull the factory line from the reservoir up to the first coupler. Placed a straight splice between the factory hose at the firewall, connecting to new aftermarket line. OD 3/8, or so, ID 2mm, quite robust. Moved the check valve to where the first coupler was. Ran another section from the check valve over to the battery tray, removed the battery, placed the reservoir on one of the battery uprights. Connected new hose to reservoir, end of selector switch issue.
Leaves a nice clean looking repair inside, no extra body holes, and is pretty much easily accessible at all components. Why the @#$@# couldn't Ford do something similar?
On a related note, the blower motor system was compromised as well. Seems the connector to the resistor had rusted between the male & female portions. The harness side kinda melted. Replaced the resistor and the harness connector, blower no longer blows fuses and has full range of control.
With all the posts I've seen, I think its just this side of criminal to not have included an access panel in the wheel well.
I spent some quality time with 2 vans at a pick n pull. Got 2 sets of hoses from the air intake area through to the dashboard switch. Considering that it took collectively 8 to 10 hours to get 2 complete sets, and a vac reservoir, the stated time by ford to replace the reservoir / hose is valid.
Discovered that with care, you can pull the check valve to the firewall and a bit through. In both cases, whether the short stub was still connected to the reservoir, it disconnected easily. In my humble opinion, entirely too easily. Considering the type of neoprene hose, and the lack of resistance, I'm inclined to believe that this is a planned obsolescence issue. Considering the hose type from the vac source to the first coupler, Ford obviously has many options.
I discovered a chewed connector at the access panel, and a failure at the reservoir.
Used the parts from PnP to replace all the dashboard lines. Used tape and stranded wire to carefully pull the factory line from the reservoir up to the first coupler. Placed a straight splice between the factory hose at the firewall, connecting to new aftermarket line. OD 3/8, or so, ID 2mm, quite robust. Moved the check valve to where the first coupler was. Ran another section from the check valve over to the battery tray, removed the battery, placed the reservoir on one of the battery uprights. Connected new hose to reservoir, end of selector switch issue.
Leaves a nice clean looking repair inside, no extra body holes, and is pretty much easily accessible at all components. Why the @#$@# couldn't Ford do something similar?
On a related note, the blower motor system was compromised as well. Seems the connector to the resistor had rusted between the male & female portions. The harness side kinda melted. Replaced the resistor and the harness connector, blower no longer blows fuses and has full range of control.
#120
04-12-2018, 10:55 AM
vettex2. Thanks for the reference to that post. I was looking at that one also and was thinking that was going to be my simplest solution vs cutting the fender well and accessing the original check valve and the reservoir. One follow up question on auric's pictures of the various locations. Is the red hose from the manifold just pushed back into the engine cowl portion of the engine compartment and then feed through the hold he drilled in the cowl? The red hose has a black rubber coupler so is that removed from the red hose, fed through the grommeted hole and then the couple is reattached to the end of the red hose inside the van? Just trying to understand that piece of the process. Everything else seems pretty straight forward to me. Thanks!