Help with "Heater" needed

[Blkhwk]

I just got back from a very cold drive across Wyoming. The temperature was about 16 degrees and while my (04) settings work fine, the heater would not respond. It seems that the only setting the unit recognizes is the coldest, so the AC works (but won't adjust) but can't get any heat (or any other setting to respond).
I'm guessing this is a "module" issue (I assume the FEM, front module) because the "readout" responds to the adjustments of the switches but gets not results, regardless of the setting.

Any help is greatly appreciated.

[DavidA]

Could be the water control valve. Usually, that causes heat instead of A/C, but still, if no heat, that could be it. Probably not the FEM since the readout works.

[Tbear]

Warm up the car, then turn on the dual climate control. Check the temp on both sides, if one is cooler than the other than the other, it is likely the coolant control valve. Turn the heat all the way up to 90 on both sides. Check the air temp, that it is flowing through the heater ducts and the fan is on high. Should be hot. Now move the temp to 60 on both sides. Check the air movement. Should be flowing through the dash vents, fan on high and the temp should be cold on both sides. If it passes this test, it is likely the coolant control valve.
Turning the temp all the way up or down checks all the doors and bypasses the coolant control valve.
One other thing you can do is run it through a diagnostic. Turn the system on. Push "off" and "defrost" at the same time just for a second, then quickly let go and push the "auto" button. It will go through a diagnostic routine. If no problems are found all the lights in the display will be lit. This test will calibrate all the doors and check all the inputs for a hard fault. If a problem is found the error code will be displayed. Push the "off" button to exit the program. If no errors, it is likely the coolant control valve.

[Blkhwk]

Local tech says I have two problems.
First the "coolant" was low in the resivoir and he thought there was an air bubble and it needed bleeding and the adding of coolant.
He topped off the coolant and it started leaking all over the floor, so we could get to the "bleeding" of the system until we fix the leak.

Secondly, he suspects the Heater Core is bad.....8 hour to remove and replace it. The cost of the new core isn't that bad, but the R&R is about $1400.... OUCH.

Has anyone here done the R&R. I have a shop manual, I think I'll give it a try unless any of you Pro's say "NO, NO. Don't do it"

[Administrator]

Could be the water control valve. Usually, that causes heat instead of A/C, but still, if no heat, that could be it. Probably not the FEM since the readout works.

I had the same problem but the other way around. I had heat but no air and they replaced the control valve and problem solved.

[Lakebum]

I don't think it's the heater core leaking. Suspect it could be the "degas bottle" and or a combo of the bottle, the coolant piping and/or the water control valve. If the bottle is bad(sometimes hard to find the cracks) do yourself a favor and use an OEM replacement not the Dorman. Might consider taking the car to a Lincoln dealer as they have more expertise with the drive train than the Ford house (at least in my area).

[steelblue5505]

My money is still on the water control valves located on pass. side of radiator just about same height as the fuse box. Look down in there you will see two sets of wires going to two valves.

[Will]

I had the same problem but the other way around. I had heat but no air and they replaced the control valve and problem solved.

We had the same situation on our way down to Savannah Thunder. Problem: heat but no a/c. Solution: Ford mechanic replaced the CCV when we got back home. Cost: about $440, parts + labor. ---Will

[Lakebum]

Was it the heater core leaking or did you luck out and find it was not as serious?

[Blkhwk]

Thanks for all the input. Here is the "update".

I pulled all the "superstructure" near the firewall and the "overflow bottle", thinking that might be producing the leak. The bottle was secure, but I replaced the main hose on the bottom, because I had to cut it to get it off to get it out (no big deal, although I'll say, it would have been much easier if I'd had hands about half the size of my current ones).
When that didn't fix the problem (oh did I mention that I'd switched out the "sending unit" from an '03 I have here, because a few people had suggested that might be the culprit. It wasn't, both units worked in the '03, neither worked in the '04).
I took it to the local Radiator shop and he worked it over for 3 days, ending up replacing the thermostat housing, flushing the system and refilling with coolant ($600), but still no heat.
. I debated about doing it myself, but I don't know that I would have found the problem and would have likely assumed it to be a heater core problem and would have moved right into R&R'ing that. That would have been a big mistake, because Tim, the radiator guy says the "core" is fine.

He speculates that, as you guys are suggesting, it needs a new heater control valve. He put his meter on it and it reads 12v on both terminal. The manual says it should be 3v on one and 9v when the other is operational.
No valves around, so I'm waiting for one, but that's next.

I'm actually feeling some "peace" about the whole thing now. It's a fix I feel confident about doing so I'll just have the part cost (around $100) and will save the 4 hour shop rate by doing it myself (looks like I'll be wishing for smaller hands again) and the other stuff needed to be done anyway.

So thanks again for the input. I can't believe how much money, time and agonizing I've been saved from the membership on this forum. If not for this forum, I would not own a TBird, just too much potential "cost" with a car that's aged, like it is.

[Blkhwk]

Sent the day R&Ring the heater control valve. I took my time and replaced a couple of the clamps from "pressure" to "screw drive", just in case someone will have to do this job again. I hear the "book" calls for 4 hours. It could be done in less, if you've done it before...........I spent the whole day. Everytime I got to a problem, I stopped, cleaned things up in the area and corrected whatever was amiss. The install was fast and easy.

My many thanks to those that suggested this as the problem.......once I considered it, it made sense....I'd fixed everything else on the way to it, so I was pretty confident about this being the "no heat" culprit.

I now have heat and one more "fix" under my belt. I'm beginning to think there isn't anything that can't be fixed on these great cars and it's tooooooo neat that someone has beeen through it before. Keep fixing and posting..........It's very helpful!