Heater/Diverter issue

I have a 2002 Windstar LX that has some weird heater related issue. When I select a mode (Panel, floor, etc...) it doesn't always select that mode. I have found that if I leave it on Panel, but turn the fan down, then when I start the van, it will be on panel. I can then change the fan speed and be fine. What's weird is that it will randomly switch to the defroster and sometimes back without me doing anything. If I don't turn the fan down or if I turn the heater system off, I can't get it to panel at all.

I think the problem is somewhat related to the temperature actuator issue I have read a lot about, but I don't know for sure. I haven't specifically tested that(it being July and all), but I don't think replacing that will have any specific impact on my current issue.

Any ideas will be much appreciated...

Z.

it was always changing what was coming out...back had heat when ac was on, heat in back ...no heat in front!

When we took it in the mechanic fixed it...i think it was the actuator and it wasn;t too much money.

good luck

Look for a vacuum leak somewhere in the lines from a/c doors to the vacuum canister under the hood.

Look for a vacuum leak somewhere in the lines from a/c doors to the vacuum canister under the hood.

Thanks. Forgive the next stupid questions:

What's an "a/c door"? Is it located under the dash or under the hood? How will I know what the vacuum canister is?

I can find my way around an engine if I have some diagrams or help, but I don't know enough to do anything without help.

Thanks very much, both in advance and now...

Z.

A/C doors are located inside the vehicle under the dash on the A/C box. The vacuum cannister is located under the hood and will look like a ball, square box, or a coffee can. There will be at least 2 vacuum lines going to it. One from the engine and one will run inside the vehicle. Sorry, I do not know exactly where it is located on your vehicle.

Hi Z
My experience is with a '96 but I'll share it as I doubt they did it much differently in '02.
First, look up under the dash near the accelerator. The A/c doors, or blend doors are actually not visible. What is visible are the vacuum motors. My van has 3 (two are actually above the accelerator and one, for outside/recirc air is below the glovebox) and each is a somewhat bulbous shaped alluminum device with two, colored, flexible vacuum hoses attached. Each motor has a partial and full travel capability, hence the two vacuum sources. An actuator extends from each motor to move its respective blend door.
In the event of no vacuum to the motors, Ford, in '96, set the system to default to defrost.
The vacuum to operate the system is produced, obviously by the engine. On my van, the accessory vacuum is tapped from the rear of the intake manifold at a nozzle about 3/8" diameter with a rubber fitting. Out of the fitting come two semi-ridgid vacuum lines one black, one red. The red disappears up under the cowl toward the right side near the top of the strut. It goes to a vacuum check valve, then a black hose goes on to a vacuum tank (plastic box about 4x5"). From the tank the black line goes through the firewall and comes out at a vacuum line attachment block also above the accelerator, where the colored lines from the motors also come together. That black line provides the vacuum, and the selector panel on the dash routes the vacuum to the appropriate hose to move the appropriate actuator for floor, defrost, mix etc.

I would think you have a vacuum leak. My system acted much like yours (slow response when selecting dash for a/c, but eventually getting it) then finally I had no response - defrost only (default). In my case I found a hole in the red line between the intake manifold and the check valve. The line had actually chaffed on the large A/C suction line coming out of the firewall. Replacing the red line seemed impossible so I fashioned a patch from a 1" length of clear 1/4" diameter tubing. I slit the clear tubing from end to end so it would slip over the red line to cover the hole and then wrapped both with duct tape. It held and my a/c selector works as advertised.

I would start at the intake manifold and work backwards. Carefully examine the semi-rigid red and then black line (not sure yours are the same color) for a hole or a kink or any other irregularity. I hope you find somethng obvious as I did.
Sorry for the long post.

Thanks for the post busboy4. That is a lot more detailed than I could have told him. We only have 1 windstar in our fleet and we very rarely see it.

Thanks for the post busboy4. That is a lot more detailed than I could have told him. We only have 1 windstar in our fleet and we very rarely see it.


What he said, and a whole lot more. I really appreciate the detail of the post. I can definitely follow these directions and hopefully resolve the issue. I will probably start tonight and work on it this weekend. I'll let you know what I find.

Thanks again.
Z.