Not a good time of the year for the heater control on the 240 to be problematic! The heater control cable is probably loose where it connects to the control valve. Before I tear into all of the dash panels, thought I'd ask just which panels to remove, and in what order? Thank you in advance for any helpful advice!

Hello Daryl:

BTDT: Classic heater control valve failure mode. You have good advice already on replacement. FCPgroton.com is the place to get the valve-- on my '92 the valve they sell (ScanTech) was an exact replacement for what was in there already. Putting it in was a pain-- there is some serious contortionism necessary to reconnect the new valve on the heater core side. It would be easier if you pull the radio and remove the heater core hose up there to give you some wiggle room below to pull the valve assembly toward the driver's side footwell. Adjusting the cable so that the valve works right is also an exercise in trial-and-error frustration.

FCPgroton.com ships the valve with a paper copy of Mike Tatra's superb photo essay (available in the archives here too) on how to do the job.

Good luck!

--
Herb Goltz, London, Ontario, Canada '92 245 w/102K mi

Hi Herb,

Thanks for your reply. Just got inside after spending a good share of the morning upside down trying to see what was going on with the control valve. I had hoped to find a loose cable from the control lever. Nope. Nice and tight. Went to the service manual to find a picture of the valve. It shows a different valve than what's in my 93. The 93 has a disc shaped valve with the hose going in at one end. The cable connects to a 1 1/2" center located lever that when pushed/pulled rotates the valve open and closed. Full travel is being accomplished when sliding the panel lever right/left. I'm going to call FCP Groton to determine if they have the proper valve.

The valve rotates open/closed quite easily, so I'm assuming that something has failed internally. Should be a bit more resistance I'd say. Don't think it can be anything else that's malfunctioning though, as simply shutting off the coolant should stop the heat.

Here's another question Herb: The service manual warns repeatedly to disconnect the negative battery terminal and a yellow connector under dash to disconnect the airbag. I can't find the yellow connector. Where is it, anyway? I don't want to have the air bag deploy when I'm under there doing contortions! Having the front panel off is a good time to replace all of the burnt out panel bulbs too. I don't think any of the control panel bulbs are working, nor is the shift lever indicator bulb. What I thought could be an hour job is turning into a full day after parts get here....par for the course I guess.

Remove the driver's side center console sidepanel by your right knee. One Phillips screw up high and a color-matched 1/4-turn plastic fastener down low. Off it comes, revealing the dreaded thermostatic valve up forward by the gas pedal. Removing also the felt cover above the pedals may give additional access. Work the control on the dash while watching the cable's action on the valve so you see which way "closed" is. Then loosen cable clamp, push valve all the way closed. Start engine and after warming a little, feel the outlet hose and see if the valve is now shutting off flow. If not, new valve. If so, tighten clamp and you're done.

Maybe.

Typical failure mode for these is to default to a 'light switch' operation....move the control one mm from some magic setting, and the temp swings wildly. If so, new valve. FCP sell a manual, non-thermostatic Scan-Tech replacement at $34. I heard that IPD are trying to re-source and again stock the OE-style unit...they were asking $55 or so.
--
Bob (81-244GL B21F, 83-244DL B23F, 94-944 B230FD; plus grocery-getter Dodge minivan, MGB, and numerous old motorcycles)

Well, you were right. The valve was bad. Ordered a new one from FCP Groton. The one that came was an exact replacement for the one in the car. Started the job on Thursday and finished on Friday at 6:30. All totaled, the job took about 12 hours. The job was frought with difficulty: first, the little clips that hold the cable to the valve body kept breaking. Broke 2 when holding the valve in my hand and trying to get them snapped into place. Finally had to use the old one after I decided to put the valve in before hooking up the cable. Getting the cable snaked into the deeply buried valve body was probably the most challenge. Ended up hooking the body up to the long hose on right, then snaking it into place. Then hooked up the other hose (left side). Then try to thread the needle with the stiff cable....a most difficult task to say the least. After 2 hours of the needle threading comedy, I got lucky. Once threaded into the valve lever, then fish the cable under the Shelob behind the dash panel and get it roughly into position behind the heater control lever on the dash panel. THEN try to get the valve body clip over the cable. This was accomplished by putting the top end of the clip into the slot on the valve body, working from the left side of the valve body. This required some deft fingerwork that causes charliehorses in your hands. Once the clip was over the cable (I consider myself just plain lucky to have succeeded with that one step...it could have also been a nightmare due to absolutely no space for working), I used a small C-clamp to squeeze the bottom of the clip into its locking position. As you can sense, the tight conditions made it a downright miserable procedure from beginning to end. Anyway, the C-clamp saved the day because there was no way that one can exert the required amount of squeeze on that stiff clip where it is located. Nearly zero finger and hand room in there. From what I can tell, the new style valve is much more difficult to access than the old style valve (it's jammed between the firewall and the backside of the heater box). My car is a 93, so that's why it had the new style valve I guess. To make a long story short, once the valve was in, I took the car for a test drive. The new valve WORKS!! Would I attempt the job again. If there is a better way to do this without breaking clips and having to fight the stiff cable, then I might try another. If there isn't an easier way, I'd be tempted to let the dealership fight with it.........

Thanks Volvodad, that's exactly the help I needed. The heater control lever on the dash panel seems a tad "loose" in the slot, so I'm hoping it's only an adjustment. Will find out this morning what is going on. Thanks again!

You know, that's exactly the opposite heater failure symptom that most people encounter. Usually the heater just won't turn on.

As I remember on my '82 240 (may not be the same for your car) the heater valve is on the left side of the console. Good luck with your repair.

- Bruce
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-- Bruce / '82 244 (323k miles!), '86 745, '87 760Ti, '94 854

Actually, Mine failed open ... still is even after FCP valve replacement ....
--
Happy Motoring Miguel '86 244 and '87 245

You mean you replaced the control valve, and the heater still won't shut off?? Or by "open" do you mean you can't get any hot coolant to the heater core?