how to fix the A/C and heater

135

Asked by Apr 13, 2008 at 11:34 PM about the 1994 Lexus SC 300 Base

Question type: Maintenance & Repair

The air blows but doesn't get hot or cold

7 Answers

6,495

sounds like you have a "stuck" air-flow door. but you might also have a plugged heater core and the A/C dont work (two different problems)

5 out of 5 people think this is helpful.
6,495

The "dry heat exchanger" is a common issue that causes this problem.

2 out of 2 people think this is helpful.
Best Answer
135

Thankyou for your info. I had a mechanic, who can't work on Lexus, overlook the system and he said the A/C unit works but the door seems to be stuck, like you said in this first post. Can you tell me a little more about this issue Please, and how to fix this.

6 out of 6 people think this is helpful.
135

Thankyou for your info. I had a mechanic, who can't work on Lexus, overlook the system and he said the A/C unit works but the door seems to be stuck, like you said in this first post. Can you tell me a little more about this issue Please, and how to fix this.

1 out of 1 people think this is helpful.
135

Can you tell me a little more about this issue Please, and how to fix this. Also what ever button i push on the LCD, it turns the A/C light on, and my LCD is broke so I can barely read it. Do you think it is the climate control unit or brain??

3 out of 3 people think this is helpful.
135

Hello again, i was told the air flow door is located on the inside engine panel, below the windshield, is that true, because I can not find any door or even an opening of any kind. And as far as the heater core, It doesn't have any symptoms, like the smell of antifreeze or leaks or fog on the windows, so I would say the control door also, but I have never heard of a dry heat exchanger, where is that located? And also are these mechanical issues or are they controlled by electrical relays or sensors that are mal functioning/ THANKYOU FOR ANY ADVICE

1 out of 1 people think this is helpful.
6,495

for the "door" it is located in the a/c and heater box. you can see the housing on your fire wall on the passenger side, you will not be able to see the "door" as it is inside the housing in the "heater box". To get the door unstuck you have a few choices, 1, you can try the can of spray (I cant recall what the name of it is right now) but the mechanic will spray it in the defrost vent and lower vents. the spray disolves the dirt/dust/grime and lubes the hardware. It will leave a slight odor in the car for a few days/weeks, depending on how much is needed. the other option is to replace the unit, this is also the most expensive option. I have heard (I never seen, nor have I done) that you can remove the unit and clean it and repair/replace the door/hinges/springs etc... I have not ever done this, nor have I ever seen it done as it is a long process. I would recommend the spray first, you might just have some dirt/grime on the door hinge. (I hope in your case that is all it is, as the can of spray is about $15 and the mechanic might charge 1/2-1 hour labor, where the cost to replace the unit assembly and labour is about a $950-1100 job). your second issue is the LCD screen, the problem you are having with it is non-repairable, the screen needs to be changed. It is a pain in the rear to need to replace it but the screen cannot be repaired. Sorry about not having an answer for you sooner, I am recovering from some surgury on my arm. I hope this info helps, please let me know how things are turning out

2 out of 2 people think this is helpful.

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