For all of the Car MECHANICS AC/Heating Specialists!

Cheekz185 · 07-26-2005, 07:43 PM

OK....Here we go. Lets start off with>> I have a 2002 Mitsubishi Galant 2.4L

In late January I was having problems with my heat! Whenever I would turn the AC knob from Cold --> Hot / Hot ---> Cold there would be this rattling noise for like 5 seconds under my dashboard in the middle. It would be a fast rattle. As time progressed It would do it every so often and everything was fine. But it started up again around March. But every time it would rattle my heat would not work. It would blow just cold air (No warm air what so ever!).

Next, The heat would not work for a couple days straight (with no rattle when switching temps), then all of a sudden it would rattle again, then the heat would work. So that was happening for a while. But now it doesnt rattle anymore and there is no heat AT ALL. A friend of mine said it mite be the "Inside/Outside changeover damper motor" He said it is like a "DOOR" that mixes the hot and cold.

I would just like to hear some of your input guys! If you can help me out that would be great!

muldrick · 07-26-2005, 07:56 PM

I almost agree with your friend, but it wouldn't be the "inside/outside" door.
There are several doors, 1. the "inside/outside" or what I call the recirculation door, 2. the "mode" door, it controls the mode ie:defrost/vent/floor, 3. the temp door: it controls hot/cold.
Each of these doors have a "changeover damper motor", or a servo motor.
Problem? Either there is an issue with the temp door, the linkage, or the motor itself.
Diagnosis? Crawl uder the dash when it makes the noise...find out which motor/door it is coming from, take the motor off and see if the door and linkage moves freely. If it does than it is most likely a bad motor.
It may be tough getting to the motor...but you CAN do it

Quote: Originally Posted by Cheekz185

OK....Here we go. Lets start off with>> I have a 2002 Mitsubishi Galant 2.4L

In late January I was having problems with my heat! Whenever I would turn the AC knob from Cold --> Hot / Hot ---> Cold there would be this rattling noise for like 5 seconds under my dashboard in the middle. It would be a fast rattle. As time progressed It would do it every so often and everything was fine. But it started up again around March. But every time it would rattle my heat would not work. It would blow just cold air (No warm air what so ever!).

Next, The heat would not work for a couple days straight (with no rattle when switching temps), then all of a sudden it would rattle again, then the heat would work. So that was happening for a while. But now it doesnt rattle anymore and there is no heat AT ALL. A friend of mine said it mite be the "Inside/Outside changeover damper motor" He said it is like a "DOOR" that mixes the hot and cold.

I would just like to hear some of your input guys! If you can help me out that would be great!

Cheekz185 · 07-26-2005, 08:22 PM

Quote: Originally Posted by muldrick

I almost agree with your friend, but it wouldn't be the "inside/outside" door.
There are several doors, 1. the "inside/outside" or what I call the recirculation door, 2. the "mode" door, it controls the mode ie:defrost/vent/floor, 3. the temp door: it controls hot/cold.
Each of these doors have a "changeover damper motor", or a servo motor.
Problem? Either there is an issue with the temp door, the linkage, or the motor itself.
Diagnosis? Crawl uder the dash when it makes the noise...find out which motor/door it is coming from, take the motor off and see if the door and linkage moves freely. If it does than it is most likely a bad motor.
It may be tough getting to the motor...but you CAN do it

Hey i appreciate your quick response. But here is the problem. It doesnt make the rattling noise any more!

I dont know what I am going to do....I have acouple more months to solver this problem...Cant wait till the last minute or else i will be freezing my balls off in the winter!

jjh221 · 07-26-2005, 08:24 PM

na get a portable electric heater that you can either plug in to your cig lighter(if they make them) or get an inverter.

muldrick · 07-26-2005, 09:09 PM

Quote: Originally Posted by Cheekz185

I dont know what I am going to do....I have a couple more months to solve this problem...Cant wait till the last minute or else i will be freezing my balls off in the winter!

1. Go to the dealer and buy a temp. control serv motor.
2. Get a repair manual
3. Find the temp control servo motor in the car
4. replace it

While you are replacing it, check the linkage and door to make sure it's not binding.

Bugbyte · 07-27-2005, 01:13 AM

I agree with Muldrick. The fact that it is intermittent is probably related to temperature/humidity, vibration or all three. If it's gone out before, it will go out again. Get the repair manual, study the layout, locate the motors and linkages and repair/replace them.

Or be prepared to freeze. Muwahahahahahahahahaha!

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