2004 Ford Expedition - No hot air blowing on driver's side, intermittent hold/cold passenger's side

[boozaro]

First, I apologize for being the guy who only comes here when he needs help. I wish I had more knowledge and was able to actually answer questions. Also, I have searched the forum and Google, but I haven't found anyone who is experiencing the same issue. Similar, but not the same. I've done everything I can think of and find recommended.


I get no hot air on the driver's side. The passenger's side is sometimes hot and then goes cold (without changing any settings) and then gets hot again, and so on.

I haven't seen the hot water valve control arm ever moving - A/C on/off, heater set to 90º or 60º, climate control on/off. I have manually pushed it in, and I get no change in the air temp output in the car.

These issues exist from the defroster to the floor - regardless of where the air is coming from. On the driver's side, I get cool air - not A/C cold, but cool. This is also from the defroster to the floor - regardless of the setting. I also have the same result when I engage the DUAL climate zones.

I have replaced the thermostat, which was bad. I also replaced the hot water valve control arm. I also replaced both the top actuator (above the heat box) and the one below - this was really fun. I encourage everyone to try this, even if it's not bad. What the heck were the engineers thinking?

Also, both heater hoses that go through the firewall are both hot.

I don't hear anything under the dash. No clicking.

The rear heat is fine.

My next attempt was going to be removing the top actuator (which I believe is the blend temp actuator?) and manually changing the blend door position, putting it back together (without the actuator) and seeing if that did anything. Without the actuator, will the airflow just blow it closed or open? Maybe the new one I put in a bad? Possible, I suppose.

I'm just grasping at straws at this point. If anyone has any ideas, I'd be very thankful.

Thanks for reading my novel. Have a Happy Thanksgiving.

------
2004 Ford Expedition EB 5.4
Dual climate control
250K

 

[whtbronco]

My thoughts were the heater valve, but it sounds like you replaced that. The heater valve is vacuum operated so if it's not moving when you change the heat settings it could be a vacuum issue. I also wonder if you have an issue with the EATC module or maybe the interior temp sensor.

There's 26 pinpoint tests for the HVAC to isolate faults within the system. So posting them is not really a good option.

Have you gotten the truck scanned with a high end diag scanner?

 

[boozaro]

My thoughts were the heater valve, but it sounds like you replaced that. The heater valve is vacuum operated so if it's not moving when you change the heat settings it could be a vacuum issue. I also wonder if you have an issue with the EATC module or maybe the interior temp sensor.

There's 26 pinpoint tests for the HVAC to isolate faults within the system. So posting them is not really a good option.

Have you gotten the truck scanned with a high end diag scanner?

Thanks for the response, whtbronco!

In the immortal words of General Beringer in Wargames...

Hell, I'd piss on a sparkplug if I thought it'd do any good.

I'm not sure how to test the EATC or interior temp sensor, but at this point, if the cost isn't too crazy, I'm not opposed to just replacing them. We're in the 20º range now, and it's just gonna get colder. It would be nice to have a heater.

You mentioned a 26 point test...I Googled that but didn't see any results. Do you happen to have a link?

I have not gotten it scanned with a high-end scanner. I have a super simple one, but since I'm just dumb enough to try to fix everything on my own, maybe it's time to invest. I am happy to do my homework on how to use it, but is there anything I should be using it to check for specifically?

Thanks again for your reply! Happy Thanksgiving!

 

[whtbronco]

The EATC module would have to be purchased used most likely. I'm not sure about the temp sensor, or even where the heck it's located. Apparently the temp sensor is located behind the gauge cluster.

Fortunately, well for me it is, this HVAC issue is an area where I have little experience with my Expedition. As usual with newer vehicles it's overly complicated though.

So the pin point test for the HVAC is 26 different tests that are numerous pages each. There's no link for them, there are links to service manuals that you can download or purchase a subscription to an online resource such as AllDataDIY or MitchellDIY. I suspect the service manual will have the pin point tests, I know for sure AllData and Mitchell do.

Here's a link to some online service manuals originally posted here by Hamfisted.
https://charm.li/Ford Truck/

OBDII scanners are available in all kinds of function levels and costs. The one thing I can assure you is that if you intend to do your own work and most of it, the scanner will save you vastly more money than you spend along with a tremendous amount of time. We got mine when we needed a body control module(BCM) for my wifes car. The local dealer wanted I think $600, might have been $700. The scanner and the BCM were $1000 and took just a few minutes to program the new module with the scanner. It was fully paid for in savings on the 2nd or 3rd use.

Probably the best place to start for a scanner is FORScan. It requires just a low cost FORScan license, Windows laptop and an adapter. FORScan can do a great deal. Since I have an OBDII scanner and I'm familiar with how to use it I prefer it.

What's new

My scanner is not super fantastic, but it's pretty darn good. It's a Zurich brand and was like $900 on sale at Harbor Freight, but they don't sell it anymore. They do sell what appears to be a comparable model again, in fact 3 tablets from the Icon brand ranging from $400-1700.

I wanted a Snap-On scanner, but it was cost prohibitive. A good scanner will save you a fortune and make advanced troubleshooting/testing possible.


After all that rambling here's some thoughts on troubleshooting with what you have. I know you said the heater core hoses are both hot, but does the outlet hose heat up at the same rate the inlet hose does? Inlet hose has the valve. The valve almost certainly leaks a tiny bit so after a little bit they will both be hot, but the outlet hose should stay fairly cool for a couple minutes after the inlet hose is warm.

The blend door was replaced, do you think it's working properly following the replacement.

 

[whtbronco]

I was thinking there's a chance this is due to the vacuum solenoid or the outside air door actuator. Have you tried selecting recirculate air to see if that helps? If it does that should rule out the outside air actuator.

 

[boozaro]

Hi Chris-

First - thank you for all of the information. I know this must have taken a considerable amount of time. I really appreciate your help.

I have tried selecting recirculate. This made no difference unfortunately. I am going to run through your messages and start troubleshooting using your notes this week.

I think there is a possibility the blend door could be an issue even though the actuator was replaced. I did manually open and close it with a stub screwdriver then I replaced the actuator and heard the signature thump sound, but maybe something happened since then. It was replaced early in the summer when I wasn't getting cold air. Replacing the actuator took care of the issue. It wasn't until a month or so ago when I fired up the heater that I discovered this new issue.

I am thinking that testing the blend door manually is a good place to start. Pulling the dashboard is probably one of the easier things for me to do at this point.

Thanks again for your assistance. I'll keep you posted.

-Scott

 

[Rickofaustin]

I hate to confess I’m having almost the exact same issue with my 03. It’s also an Eddie Bauer. I get zero heat out of my front vents. Flush the cooling system flushed the core with hot CLR, the valve seems to be working… Is it likely that the engine Water pump needs to be replaced? I have not yet replaced the thermostat. What was wrong with your thermostat?

 

[whtbronco]

If the water pump is not leaking, the weep hole is not dripping and the engine temperature remains stable in operation the water pump is fine. If it fails you'll over heat pretty quick, usually they leak first though by design.

The thermostat can be slow to react(open/close), stuck open or stuck closed. I guess it could also get plugged with goo due to not changing the coolant nearly often enough. Slow to react the engine temp will be very slow to cool down or warm up whichever is required. Stuck open the engine will take forever to reach normal operating temp, stuck closed and the engine will over heat in just a few minutes after cold startup. Thermostats are fairly quick cheap and easy to swap if needed. Just make sure you have a new gasket(an o-ring) and 1-2 gallons of coolant on hand.

If you flushed the cooling system including the front heater core and the engine temp is normal while it's running the thermostat and water pump are not likely the issue. If the rear heat works as expected the water pump is moving coolant.

 

[boozaro]

I hate to confess I’m having almost the exact same issue with my 03. It’s also an Eddie Bauer. I get zero heat out of my front vents. Flush the cooling system flushed the core with hot CLR, the valve seems to be working… Is it likely that the engine Water pump needs to be replaced? I have not yet replaced the thermostat. What was wrong with your thermostat?

The thermostat had failed open, so the engine was never getting that hot. The temps here are around 15º-20º. The temp gauge would register around the second or third hash mark.