greetings. I am a new user and was hoping someone could tell me how to remove the portion of the dash to see what's up with no heat coming into the cabin. Just blows cold. I have read the threads on the motor control valve which could be the culprit, but I would like to see if I can get into the dash area myself before dropping $$ taking it somewhere. I am usually a pretty decent do-it-yourselfer. Thanks.

I have actually removed the motor control valve (it's actually the actuator that simply pushes a rod attached to a valve) and yes, if I understand you correctly, it is the thread or the teeth on the gears within the motor assembly. The DC motor inside has a pinion attached to the end of its shaft and it in turn turns a cog which turns another cog which turns another cog which then turns the actuator arm. *whew!*. It's amazing how much they charge for this motor assembly. It is such a simple device.

Incidentally, the clicking noise that usually accompanies this problem (like something hitting the blades of a spinning fan) is made by the worn pinion turning against the cog.

The way it works is that the 12V supplied to the motor reverses its polarity when you turn the temperature knob from full cold to just past the second detent towards warm and vice versa.

The problem with this design is that when the motor turns the actuator all the way to the end, there is no circuitry or switch that shuts off the voltage to the motor, so the motors pinion thread is constantly pushing against the cog. Over time, the constant back and forth operation of the actuator wears down the pinion and and gears until finally when the motor is actuated for the last time, the pinion gets jammed against the teeth of the cog to the point where the motor no longer has the torque to undo itself when the voltage polarity is reversed. This motor should have had more torque.

I haven't figured out a way to prevent the motor from jamming yet but I'm working on it. It's one of those things that seems too insignificant to spend hundreds of dollars to get repaired, yet it really sucks to drive in the winter with no heat! So I totally understand you wanting to do this yourself.

To remove this motor, you pretty well have to remove the entire bottom half of the dash. I have a 2003 Galant ES so hopefully these pointers will apply to your car. Start with the glove compartment then the entire bottom half of the dash... there is no getting away from it... to take out one piece, you have to remove another, and another, and so on. You have to remove the frame around the stereo and temperature/fan controls.

Basically, if you can remove the bottom right side completely, then that's all you'll need to remove. The motor is located deep inside mounted on the right wall of the centre console right behind the stereo. It's a pain to remove as you first have to undo a few wiring connections and remove a black box (no clue as to what it is... some kind of control box is my best guess) from a bracket. This slides out towards the back. Undo its connector and put it aside.

Now here is the fun part. Unscrew the three screws that mounts the bracket that held the mysterious black box. Use a stubby Philips driver if you have one. Luckily I have a screwdriver with a snake extension that can be bent into tight spaces.

Now unscrew the the three screws to unmount the motor.

I'm sure I've missed a step or two, but if your as handy as you say you are, then it should be pretty obvious what the next steps are.

I wrote this just after figuring out what the problem is. Now I have to put everything back together! I just hope I don't end up with a screw or two left over! :)

Hope this helps.

I did it! And it works... at least for now...

I took the motor apart and tried to find a way to prevent it from jamming. I tried using a silicone spray lubricant and that didn't work. Not having any other type of grease, I thought I would try good old Vaseline. Since it is a petroleum jelly, I thought what the heck... it can't get any worse... but guess what, it works like a charm! It doesn't get rid of the grinding noise, but it does allow the motor to unjam itself with what little torque it has. I just slathered on a gob of Vaseline over the pinion (or worm gear) and over the teeth of the other gears, and put the motor back together.

Now, I have no idea how long this will work for, but I did test it several times after mounting the motor back into the dash, turning the temperature dial back and forth, and it didn't jam. For now, I'm not going to adjust the temperature dial all the way to full cold for the entire winter nor do I have any reason to... why tempt fate? The motor activates at the second detent after full cold so there is alot of room to adjust the temperature to whatever is comfortable without activating the motor.

If you do happen to activate the motor, you can reverse it back to warm immediately before it stops at full cold and possibly jamming itself again.

Obviously, there are better alternatives to using Vaseline. It was what I happen to have on hand and was too lazy to go back to Canadian Tire (a major automotive supply chain here in Canada) after having been there already to buy the silicone lubricant. The point is to use the slickest grease you can get to prevent the motor from jamming, preferably something that is rated for a wide temperature range.

I hope this helps anyone who is mechanically inclined enough to attempt this repair on their own.

Take care!

about how long did it take to complete the job,,Thanks,Mark

I'll be attempting this job on my friend's 2003 Galant ES tomorrow. Today I replaced the thermostat thinking this was a classic case.

I am hoping that the problem is in the control valve. Once warmed up (fan cycling on and off) I noticed that both heater hoses were not hot. Is this a symptom of the control valve problem?

I do not hear any clicking noises when switching from hot to cold.

Any help/advise is greatly appreciated.

If this forum accepts pictures, I'll be happy to provide shots of the process.


Cheers.


UPDATE: Once the air was worked out of the system by some highway driving, the heat came back. Topped off the antifreeze and all is well.

Hi. I had the same problem last winter...I'm a "ameteur" who tried to remove the dash but got stuck since i don't have all the tools to make removal easy. I end up going to the dealer and Part 180 + labour 115 + CDN taxes total 340!