HVAC controls links-Hard to turn problem
Oct 15, 2009, 05:33 PM
#62
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I was lost reading your question. Punctuation is nothing to be afraid of. 
How It Works
The knob turns a gear. The gear swings lever (which I'll call "A"). The lever pulls a cable (just like the cable for brakes on a bike). The other end of the cable swings a lever (which I'll call "B"). That lever is connected to yet another lever ("C") via a messed-up kludge (pics: https://www.evolutionm.net/forums/7517475-post28.html). The end of that lever has teeth which rotate a gear. That gear somehow causes the blend door to move. The position of the blend door dictates your air temperature.
What Goes Wrong
Very common: The connection between levers B and C is an unholy kludge which makes the baby Jesus cry and makes the knob hard to turn. There are redesigned parts which cost $25-ish and which can be replaced without a lot of technical know-how. Bring a short screwdriver and bandaids for scraped knuckles. You'll probably invent some new cursewords while lying on your back trying to get your arms up there.
Less common, but all-too-frequent: The blend door itself can have trouble moving. There are redesigned parts for this, too, but replacing the door requires dropping the dash. This is non-trivial for an average mechanic, as well as time-consuming. It's expensive ($500-ish) for the dealer to do it.
Even less common: the cables can get tweaked or come loose (the ends of the cable sheathing have to be fastened securely for the cables to work).
Ideas For What You Can Do
As a short-term solution, you can see whether you can move Levers B and C by hand. After my first few trips under the dash, I got to where I could adjust them while sitting in the driver's seat.
I bought the replacement link-lever kit, and while I had the levers off I found I could rotate the gear that moves the blend door easily by hand. If you can't, that implies your have a blend door problem.
Other people have pulled out the radio and looked at the operation of their cables while rotating the knobs and found that the cables were messed-up.
Good luck!
How It Works
The knob turns a gear. The gear swings lever (which I'll call "A"). The lever pulls a cable (just like the cable for brakes on a bike). The other end of the cable swings a lever (which I'll call "B"). That lever is connected to yet another lever ("C") via a messed-up kludge (pics: https://www.evolutionm.net/forums/7517475-post28.html). The end of that lever has teeth which rotate a gear. That gear somehow causes the blend door to move. The position of the blend door dictates your air temperature.
What Goes Wrong
Very common: The connection between levers B and C is an unholy kludge which makes the baby Jesus cry and makes the knob hard to turn. There are redesigned parts which cost $25-ish and which can be replaced without a lot of technical know-how. Bring a short screwdriver and bandaids for scraped knuckles. You'll probably invent some new cursewords while lying on your back trying to get your arms up there.
Less common, but all-too-frequent: The blend door itself can have trouble moving. There are redesigned parts for this, too, but replacing the door requires dropping the dash. This is non-trivial for an average mechanic, as well as time-consuming. It's expensive ($500-ish) for the dealer to do it.
Even less common: the cables can get tweaked or come loose (the ends of the cable sheathing have to be fastened securely for the cables to work).
Ideas For What You Can Do
As a short-term solution, you can see whether you can move Levers B and C by hand. After my first few trips under the dash, I got to where I could adjust them while sitting in the driver's seat.
I bought the replacement link-lever kit, and while I had the levers off I found I could rotate the gear that moves the blend door easily by hand. If you can't, that implies your have a blend door problem.
Other people have pulled out the radio and looked at the operation of their cables while rotating the knobs and found that the cables were messed-up.
Good luck!
Oct 15, 2009, 05:43 PM
#63
Ok so my 03 im pretty sure has never had the cabin filter changed and idk where it is. My heater control worked up until a few weeks ago but flipped from cold to hot really hard. Now it can go all they cold but only about 3/4 the way to hot, and I can not here the door flip and it stays cold in the car. What actually causes it to not switch over to hot im lost reading this thread on where to go with fixing it? its snowing now and I want to try to fix it this week so my girlfriend doesnt yell at how cold it is in the car.lol Should I get new gears, it feels like something is stopping it from turning completely to hot
On cabin air filter. The '03's did not have these. That's an easy fix, too. Search in the DIY section. The filter goes behind the glovebox. I think the filter was about $20, too.
I don't think the issue with the heater knob is related at all to the cabin filter. The gears are just a crappy design. The replacement gears have been redesigned.
Oct 15, 2009, 05:44 PM
#64
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Status Update
As for me: the control unit came in today and I installed it. It went reasonably well. The biggest problem was the 90 degree heat.
As some others have reported, the knob was very hard to turn initially. Felt like it was going to snap. I moved the link-lever stuff by hand and put some lithium grease in the gears, and it moved a LOT better. Better than the old one had ever worked for years.
It's still not perfect. But I can live with it. Especially because I saved $700+ by not having the dealer do the work.
Some info about the part: the control unit comes with the cables attached, and with a new dash panel and knobs.
A sincere thanks to everyone who posted info that helped my make this repair!
As some others have reported, the knob was very hard to turn initially. Felt like it was going to snap. I moved the link-lever stuff by hand and put some lithium grease in the gears, and it moved a LOT better. Better than the old one had ever worked for years.
It's still not perfect. But I can live with it. Especially because I saved $700+ by not having the dealer do the work.
Some info about the part: the control unit comes with the cables attached, and with a new dash panel and knobs.
A sincere thanks to everyone who posted info that helped my make this repair!
Last edited by Berserker; Oct 15, 2009 at 05:48 PM. Reason: Added Thanks
Oct 15, 2009, 07:21 PM
#65
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I purchased the revised gears from my local dealership and overall I would say that anyone with common sense can do it successfully. The knob now turns very well for being a climate control system that is "geared" by gears (no pun intended) unlike my dads Honda. My only problem and reason why it took my like an hour-ish is because the door gear wasn't lined up properly the first time. Also, if I didn't have carpal tunnel b4, I have it now. 
Just be patient and be aware of how the gears work/look before getting into it.
Price: $23 after shipping
Time: somewhere between 40-60mins
Result: Frustration dropped ten-fold, saved money/damage, and I get to keep motoring on.
Just be patient and be aware of how the gears work/look before getting into it. Price: $23 after shipping
Time: somewhere between 40-60mins
Result: Frustration dropped ten-fold, saved money/damage, and I get to keep motoring on.
Oct 15, 2009, 11:50 PM
#66
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For anyone in the future who is going to try this: there's a part that sticks out of the door gear that has to line up with an indentation on the lever which turns it. I found that the easiest thing to do was line them up before screwing the lever down. Then I tested just how that one lever worked with the gear before putting on the other lever which attaches to it.
A-freaking-men. I have a gnarly gash on my middle finger knuckle. It bled profusely and I thought I might have to get a stitch in it. I think it'll be OK without an ER visit, though.
Congrats! You did it right. I'm $370 poorer because I snapped that friggin' knob off.
Oct 16, 2009, 05:07 AM
#67
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Oy....I went to the dealership yesterday and they wanted at least 800.00 because they said they'd have to take the dash apart.
I'm going to try the TSB that was posted though because I can barely turn to heat and it's getting f'n cold here in rainy GA.
I'm going to try the TSB that was posted though because I can barely turn to heat and it's getting f'n cold here in rainy GA.
Oct 19, 2009, 08:47 AM
#70
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I just got my car back from Traffic Jam Motorsports over here in Buford, GA. They re-greased the gears and now my car blows out lukewarm heat versus just cold air. Do you guys get really hot air or just warm?
I just think it's weird how the AC is ice cold but the heat is just warm.
I just think it's weird how the AC is ice cold but the heat is just warm.
Last edited by Sixth_Vang; Oct 19, 2009 at 08:49 AM.
Oct 19, 2009, 01:35 PM
#71
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I spent 12 and a half hours fixing the problem, I bought the links but not the blend door.
I fixed mine just pressing and blending the blending door itself. I figured out the the problem is all about the round shape of the door not matching the rails of it. It always got stuck half way. I recommend to use grease and to clean all the ducts and the cooling panel too. At the end it really works like it should. Now I only have a lower back pain.
I fixed mine just pressing and blending the blending door itself. I figured out the the problem is all about the round shape of the door not matching the rails of it. It always got stuck half way. I recommend to use grease and to clean all the ducts and the cooling panel too. At the end it really works like it should. Now I only have a lower back pain.
Nov 5, 2009, 08:17 PM
#73
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Foor For Thought On Repair
I disassembled my old unit, and when I put it back together I used the shaft from the rightmost knob in place of the broken shaft for the temperature knob. As far as I can tell it functions properly.
So, for you guys snapping off your knobs: maybe two of you can pool your resources to buy one new unit and then build another functioning unit from the carcasses of the two dead units.
Just food for thought.
So, for you guys snapping off your knobs: maybe two of you can pool your resources to buy one new unit and then build another functioning unit from the carcasses of the two dead units.
Just food for thought.