I'm new to the forum. My 2002 EB expedition has several things going on with the heat and air I think...based on what I am reading. I have been without heat now for 2 winters and am ready to dive in and attempt the repair. I haven't seen any videos on the 2002. I have seen some 2003 and some 1999. I'm not sure if the 2002 EB is any different and should I be looking at the older or newer.

Now for what is going on with it. First when you turn the heat on it automatically goes to defrost. From what I've read that should be a vacuum leak. Is that correct ... what is the best way to find that. Seems that will be the easiest issue. I think that the air is mixed...sometimes hot air and sometimes cold even when the system is off. I thought that might be the blend door. I went ahead and ordered a blend door and the actuator based on what I was reading...that those 2 parts fail a lot. I thought it might be best to replace both even if only one is bad. I have seen a couple of videos that repair these two parts by removing the console and cutting a hole behind the glove box. Would you recommend this method? Do you have a video you would recommend? I really don't want to take the dash out...ugh! Hoping to get after it this weekend.
to get it done this weekend.

 

Yes it's a vacuum leak and if you can hear a hissing sound you're in luck with finding the leak. The better way to find it is by using a smoke machine. It pumps smoke into the vacuum line system and the smoke comes out of any leaks.

For the blend door, if you haven't yet found the website for heatertreater go here and watch the video.
Ford Expedition '97-'02 - HeaterTreater

 

Started with the console removal. I can't seem to get the wire harness for the CD player out. Is there a trick that I am missing? Everything else came out easy.

I checked the function a little more. When the system is on floor it blows heavy out the defrost. When it is on floor/defrost it blows a very little on the floor and a lot out defrost. When it is on panel it comes out the panel strong and a little out defrost. When it is on panel floor most comes out panel and a very little on the floor. None is very warm though. The AC Seems to be working fine. Blowing out the panel and is cold. I'm working on replacing the actuator motor and the door. I purchased both dorman. It came with the door instructions going through the glove box. In the process of cutting it open now. Hopefully I'm on the right track. There still may be an issue with the heater coil, but wanted to try easy first.

 

Well...it seems that the blend door and the actuator are functioning properly. After I cut it open I functioned the door. The door closes all the way when the heat temp. is high and opens a little as I change the temperature. When max air is on the door is closed tight toward the engine bay. There still is very little warm air coming out. The temperature control really didn't change the air temperature. I really thought it was the blend door...ugh!! Suggestions as to what to check next. I have visions of having to replace the heater core and I don't want to.

Still not able to remove the wire harness for the CD player. It is really in there and I can't find the way to release it. Shouldn't be so difficult!!

 

For heat, you must first have hot coolant circulating through the heater core. Have you checked the lines to see if they're HOT? When the engine is at operating temp, those lines should be >180F.

 

Thank you for your reply...I checked the hoses. The inlet is fairly hot...but I can hold it without it buring. I see on the forum I need to check the temperature. The out hose isn't as hot. I don't think it is coolant, but could be clogged core or maybe thermostat?. I do think vacuum leak is involved too. In the summer when the air was on it also cut out when RPM's were high. Reading I found that that is usually a vacuum leak also. Still checking

 

Nope. You have a circulation problem in the heater loop only (in regards to the specific issue of little to no heat).

Unrelated issue. That's usually a slipping compressor clutch if by "cutting out" you mean the compressor disengaged.

 

You have a restricted/plugged heater core. First try back-flushing it. If that doesn't solve the problem then the heater core will have to be changed.

 

It could be the heater core is plugged, it could also be other things.

 

I would've though so too, until he said the "in" heater hose was hot and the "out" one was cooler. Just my 2-cents.

 

The description of "fairly hot" may indicate a somewhat tepid temperature at the inlet. In a correctly operating system, that hose should be DANGEROUSLY hot. Since there's some cabin heater output reported, there's definitely going to be a very noticeable temperature differential noted between inlet and outlet as there are some BTUs being transferred to the air from the coolant.

First thing to do is to check the coolant level and verify it is adequate in the system, then check the operation of the thermostat. If both of those are verified to be withing operating parameters, then back-flushing the heater core would be an appropriate step to see if there is actually adequate coolant flow.

 

Yes you're correct that the first thing to verify is that the engine is up to the correct operating. But regarding the inlet hose, even if the engine is up to temperature a restricted core reduces the flow even within the inlet hose. This gives the cold winter air and radiator fan time to cool the coolant before it reaches the firewall. This can leave the hose feeling cooler than it should, even with a correctly heated up engine.