I know that this problem has been addressed many times on this forum however, I need to ask anyway.

This is a 1999 Ford Expedition EB 2WD. There is no heat coming out of the front. It is all cold. It also has rear air and as far as I can tell, it is cold also.

I have check both lines on the side of the firewall and both are hot.

Vehicle has climate control and I have looked at the book but it seems difficult to understand at this point.

I want to determine if it is the control box/head in the instrument panel is bad before I proceed. Additionally, although I have searched the internet many times, I have not found a vacuum schematic that would help with trouble shooting. I am working under the assumption that it is a vacuum and/or control head failure since I hear no noise at all when the various options are selected on the climate control system.

I am aware of the door problem and, although time consuming, I can make the necessary repair if needed. I just want to rule out vacuum/and control head of climate control system first before I waste a lot of time as others have done.

Any assistance, recommendations, and/or procedures for testing/checking would be sincerely appreciated. This is my daughters car and she is freezing right now as is her husband. His car, 1999 Exp 4X4, needs a heater core which will probably be done next week. Until then they are using my 2004 Exp EB 4X4 that works fine.

A lot of work over the next week and need whatever assistance you guy can provide. I am 67, disabled, and overloaded to say the least. Presently restoring two classics (65 Mustang FB/64 Chevelle Malibu 2 Dr Sport) which is sometimes overwhelming.

Thanks in advance.

 

Is this a manual control system or a climate control?

 

Climate Control

 

I think I would start by removing the control head and making sure that the vacuum lines are all connected and also check the lines for leaks, at least as far back as you can. Have you checked your engine's vacuum reading? What is it? You should also check all the vacuum lines inder the hood, especially the 90* ones as they like to go bad in the middle of the bend.

 

Thats what I have been thinking would be the first move. Is there somewhere I can find a complete vacuum diagram on the Net. The book I have does not have it and I have been searching for a couple of days. May have to get another book but hoping won't have too.

 

I'm sure there is a schematic somewhere but, I have searched my Ford service manual and cannot find it. That's what I get for buying an eBay manual. It was cheap to buy but has a few shortcomings. I guess I got what I paid for.
If you take a vacuum reading from the intake manifold and get a low reading it would indicate a vacuum leak. I would operate the heater switch while taking the readings to see if there is a fluctuation when switching.

 

Expedition Heat Air pictures by 1964Malibu - Photobucket

The above link is provided to help with what I have done.

First of all, I have checked and rechecked all the vacuum ports. Everything is functioning as it should.

I removed the dash and the heater box cover and there is no apparent failure.

The blend door appears to be in the correct position for getting heat into the vehicle. I did not check the Blend Door Actuator since it appeared to be operating normally. See the picture in above link.

I have also provided pictures of the other components check and verified for operation.

Even though the blend door is in the correct position, I think, for heat, still does not get hot. It is warmer than freezing but the vehicle front and rear heaters are not providing the heat you would expect at the lowest temperature.

Just in case, I have also provided a picture of the center ducting at the point where the blend door actuator is located. Could use some help on "How to Get Out".

Assuming everything is functioning correctly as described, what else is there?

Is it possible that the heater core itself is bad. I checked the input and return lines when the vehicle was running. Both lines were hot.

Assuming it is the heater core, can someone explain in detail how you get the lines in the engine compartment to disconnect from the stems of the heater core. Barely enough room for my grandsons hand, age 11, let alone mine.

If it is the heater core, I may have to cut off and figure out later.

Please look at the pictures and let me know what you think and advise me of the next step.

I am open for anything at this point except C4.

Thanks

 

C4 always works great! Still checking. How much manifold vacuum were you pulling at an idle?

 

The quick connect fittings are great if you have the special tools that are needed, Thank you Ford! I ended up cutting mine and put it together the old school way.
Why not disconnect the heater hoses at the engine and put the house hose to it and see what flushes out?

SECTION 412-00: Climate Control System — General Information 2000 Expedition/Navigator Workshop Manual

GENERAL PROCEDURES

--------------------------------------------------------------------------------

Heater Hose Couplings

Special Tool(s) Heater Hose Disconnect Set
412-042 (T85T-18539-AH)

Disconnect

WARNING: The engine must be off, fully cool and the cooling system fully depressurized before attempting to disconnect any heater water hoses. Failure to comply with this warning can result in serious injury or burns from hot liquid escaping out of the engine cooling system.

Depressurize the engine cooling system.
Push the heater water hose toward the tube to fully expose the locking tabs.
NOTE: When compressing the white coupling retainer, the Heater Hose Disconnect Set must be perpendicular to and on the highest point of the coupling.

Push the Heater Hose Disconnect Set over the coupling retainer windows to compress the retainer locking tabs.

NOTE: A slight twisting motion while pulling on the heater water hose may be necessary to assist in the removal.

Pull the heater water hose away from the heater core tube.

Plug the heater water hose.
Remove the white coupling retainer from the tube.
Spread the retainer tabs apart and slide the retainer off the tube.

Discard the retainer.
Connect

Clean the tubes and lubricate with Ford Rubber Suspension Insulator Lube E25Y-19553-A or equivalent meeting Ford specification ESF-M99B112-A.
Install a new coupling retainer, spacer, and lubricated O-rings into the quick disconnect coupling housing.

Push the heater water hose with a quick disconnect coupling onto the tube.

Make sure the coupling is fully engaged by lightly pulling on the heater water hose.

 

I think you would be wise to replace the blend door while you are in there. The one you have may last forever and then again, it may break the day after you get it back together.

 

Didn't check yet. I tested all the system with a vacuum pump.

 

[quote=Moto Mel;11063476]The quick connect fittings are great if you have the special tools that are needed, Thank you Ford! I ended up cutting mine and put it together the old school way.
Why not disconnect the heater hoses at the engine and put the house hose to it and see what flushes out?


I am going to do that next. Still wondering if the heater core being clogged would cause the problem.

Also, how to get the blend door actuator out easily. Going to change the door for the same reason you suggested.

 

[quote=Moto Mel;11063476] I ended up cutting mine and put it together the old school way.

Old School Question. Mine has two T's off the hoses. I assume that the T's go to the rear heat. Did you replace all the lines or just pick up near the firewall with a hose and clamp??

Still looking for an easy location to do a back flush. This car is designed for a shop mechanic and makes things difficult to do anything. Haven't found anything easy yet except for brakes and alternator. Replaced the Fuel Pump on both my daughters a few months ago and it wasn't too bad. Learned very quickly though that the filter needs to be changed on schedule.

 

By the way, you asked me about manifold vacuum twice. Although I haven't check, is there a flow valve or something else in the engine compartment that could be impacting the amount of water getting to the heater core?

I know there used to be a vacuum modulator that opened and closed the water flow but not familiar enough with the Expedition Yet to rule that out.

 

The vacuum check is to be certain there is enough vacuum to operate the controls reliably. I believe the vacuum operated flow valve is still used on the F250s, Excursions and larger trucks and they are designed to operate for heat and at Max cool it shuts the flow off entirely. Every once in a while I start considering how to adapt one to my truck.