Hi Guys, I've got a 2000 E250 and the heat and ac is stuck on the vents. I know with a vaccum leak it should default to defrost. I'm thinking it may be a stuck door or an actuator. Any ideas what it may be?

I also have the speedometer problem that seems to be common on these vans. It's the one where the speedometer goes to about 40 and then stops. It did pass forty once after starting this problem. It happened when I was passing another vehicle. However when it did it went all the way up to 100 and then back down to 50 and kept fluctuating between the two until I slowed below 40 at which point it once again stopped at 40. I've not really seen a fix for this other than replacing the speedometer. I did change the speed sensor in the rear and that didn't seem to help. Again, any idea?

Thanks in advance for any help.

 

You are correct about the default air flow being defrost--from your description your vacuum system isn't leaking though.

To me this sounds like the vacuum portion of the Function Control electro/vacuum switch isn't doing its job--this is this the one that selects Vent, Defrost, A/C etc. Remove the access plate near the windshield on top of the dash, engine running and switch from one function to another. The vacuum servos should move---if not then then best guess is the selector isn't working properly.

Check all your vacuum routing too--the hard plastic lines have been known to develop issues over time

I've not seen this speed issue as all that common---I've owned or had access to 6 E-Series ranging from a '97 through an '06 and not one has had this issue. You could have a problem with the speedo portion of the cluster or the Vehicle Speed Sensor is failing. However if that's the case your transmission might not shift correctly. I'd suspect a loose wring connection to the cluster, perhaps right at the cluster connections. Could also be a failing cluster--if you have access to a known working cluster try swapping them out to see what happens.

In the future I'd post only one issue per thread; multiple issues in one thread can cause a cure or fix for one of them to get lost in the replies.

HTH

 

Thanks JWA. I did pull the panel and the door arm wasn't connected. The door moves freely by hand, so I don' think that it. I turned the selector and the servo didn't move. I pulled the vacuum line of the back of it and it didn't feel like there was any vacuum. I guess that means it the function switch?

On the Speedo, I Googled the problem and some said it was fairly common that why I posted that. I have already replaced the speed sensor and there was no change. I should say that this van only has 45k on it. That's one reason I'm surprised that I have an issue with the speedo.I guess I'll have to pull the cluster and check the connections. Is there anything else that would affect the speedo besides the VSS?

 

Most likely it is the vacuum portion of that switch---this schematic for the vacuum routing will apply to your 2000 E-Series:




For those search results were there any common causes for this problem? I agree the relatively low mileage would seem to not have failing parts however your van is 19 years old so that could have an effect. Electrical connections have been known to corrode in place interrupting current flow. I'd pull the cluster out, disconnect and clean those three connectors from the wiring harness. If you can find a dedicated electrical contact cleaner that might be helpful---this assumes it is the connections to the cluster.

Also make sure each wire of each connector is secure in the plug. It would be rare one of those were an issue but anything's possible.

HTH

 

Hi JWA, I haven't had time to trace the line yet. However, I did pull the cover and found that the vent door isn't connected to the motor. However, none of the motors move when I turn the selector ****. I guess that would narrow it down to the selector, correct?

 

I would say yes but first check for vacuum at the connector under the dash access plate, should be the black incoming line. Once you know vacuum is available if you have a hand-operated vacuum pump and various fittings you could individually test each port to make sure the servos will move under vacuum.

By "connector" I mean this:


This is located under the dash access plate. That image shows the end of the harness connected to the dash pod---check for vacuum at the chassis side where that ^^ parts mate.

HTH

 

Hi JWA, sorry for the delayed reply. It's been pretty cold and I haven't been able work on the van much. What I have learned is that one of the doors that switches from vent to defrost is not connected to the actuator. That led me to speculate that it may not be stuck on vents after all and maybe it had actually defaulted to defrost but since the door wasn't connected the airflow never changed. I looked up under the passenger side dash and found a connector in the vacuum line. It only has two lines one, I believe, is the main line coming in from the manifold. It is a black hose. The other is a white hose that, I believe, runs from the control switch in the dash to the re-circulation door. I pulled this connection apart and there was no vacuum on either line. It seems this has limited the area of the problem to the engine compartment. I pulled the connection apart near the oil fill tube where the red and black lines meet. I had vacuum where these two meet. It seems the only thing left is the line between the two, the check valve. or the reservoir. I've heard these are very hard to get to.

Upon further reflection it seems that it has to be either the reservoir or a broken line. If the check valve was bad I'd still have vacuum, it just wouldn't hold, correct? If the reservoir was leaking air would enter the system and cause the loss of vacuum. This would hold true for a broken or leaking line.

Also, I saw in another thread that you were going to pull your battery and tray and see if it was possible to access the reservoir from there. Were you able to do that?

 

You are correct there

I stopped looking for the original reservoir mostly because there are too many alternatives to replacing it. All you need to do is install some sort of vacuum reservoir between the intake source and the point in the air flow control system that functions the same way. Personally I'd use a Ford reservoir (which has built in check valve) installed inside the cabin near the heater core box. There's more enough room up under the dash just below the passenger side air bag "shelf" to do this.

I used this Ford part:
IOW its not WHERE the vacuum reservoir is physically placed as long as it's in the system before the vacuum distribution connector. Consult the diagram I included earlier.

HTH

 

Hi JWA,
I finally got out to check the vacuum lines. It's outside of the cab. I ran a hose from the vacuum connection at the oil filler tube into the cab where I cut the line coming into the cab through the firewall. I hooked up the tube and everything works. So, I'll just have to add a reservoir and check valve. I'll probably add it under the dash inside.

I also pulled the instrument cluster and looked at the speedometer connections. They all look good. I pulled them off and inspected the needle by blowing into the bottom of the cluster and onto the speedometer needle is spun easily. I also looked to see if maybe it was rubbing the face of the cluster but it's not. There is plenty of clearance between the needle and the face. I checked the wires on the connectors and they seemed tight. I reconnected it and will drive it to see if the needle still sticks at forty. I guess if it does I'll have to send the unit off for repair.

 

Good news on the air flow thing Butch---good going there.

I didn't ask but did you ever notice if the odometer advances even though vehicle speed isn't registering?

If you're not overly concerned with the odometer's reading relative to the vehicle's actual accumulate mileage you can find a nice complete used cluster through eBay. I've bought a few different types fitting F- & E-Series trucks for various projects--look for a seller who offers no-hassle returns.

Repair-wise I found this seller on eBay: Cluster Repair. No affiliation but his feedback is near perfect and I get a good vibe from him--can't explain that part but I'd give him a shot at repairing at least one of my clusters if ever needed.

HTH