[Rfong]

When I turn the rotary switch to my AC fan, it speeds up with every notch and it sounds louder but there is no change to the amount of air coming out of the vents. If AC is set on Cold, there is a small stream of cold air coming out, but it never gets to the full blown volume of air that it once produced.

This does not happen all the time, but intermittently which of course we all know makes it impossible for the dealer to diagnose.

Any ideas?

 

[Lckitty]

Flap to guide which way air goes (defrost, face, feet) may be stuck??

 

[invictusmaneo]

check to see if it changes positions like LCKITTY stated.

Then, take it in to the dealer and have them check the car. If your AC is ice cold but doing what you describe, as in you can hear the fan speeding up but not producing any extra flow, your coils are freezing up and blocking the flow. There has been an issue that just started popping up (according to LCUSA) that some ECUs are reading the temp sensor in the HVAC box improperly, causing them to constantly read hotter than reality. This causes the coils to freeze up. On my car for example it was stuck on 26 degrees Celsius, even after a reflash of the latest software.

On my car we haven't completely ruled out it being a temp sensor failure vice an ECU problem, and the ECU problem doesn't totally make sense to me.....but I have an HVAC box on order as the sensor is non serviceable, the whole box has to be replaced. That is a front clam off job, 8+ hours. According to LCUSA this has just started popping up.

With my car, I just have to manually cycle the AC button on and off, so that it doesn't stay too cold for too long, as it still blows ice cold. Annoying, but at least it cools the car down until we get it fixed.

 

[Rfong]

Flap to guide which way air goes (defrost, face, feet) may be stuck??

This would be like a diverter in a house air duct? Where is it located in the Evora? That's what the malfunction feels like. Sometimes the AC is working fine, then suddenly the air flow shuts down to 10% of the flow. Same sound from the fan, just less air. Then, just as suddenly the air comes back full force.

 

[invictusmaneo]

There is a motorized unit in the dash that rotates to divert the air to the appropriate area. On the elige these failed relatively often or got jammed. After seeing my issue with the dealer tech, he said he had not heard of a failure on the Evora's part.

Witout pulling the dash you won't be able to check in detail yourself, but you can symptom check to see if that is what is causing it by cycling through the various positions to see if air comes from each. If it is still moving, and you don't hear any strain, then it is likely not the culprit.

If you read my post as described, I had similar symptoms...as I was driving, I would turn the AC down or the fan off, and the coils would start to thaw out (they drain to the underside of the car) and eventually flow would return to normal...but if I turned the AC higher it would slowly seize back up. There are several pieces to the AC system that can cause this, but chances of failure on some are much slimmer than others.

 

[Rfong]

check to see if it changes positions like LCKITTY stated.

Then, take it in to the dealer and have them check the car. If your AC is ice cold but doing what you describe, as in you can hear the fan speeding up but not producing any extra flow, your coils are freezing up and blocking the flow. There has been an issue that just started popping up (according to LCUSA) that some ECUs are reading the temp sensor in the HVAC box improperly, causing them to constantly read hotter than reality. This causes the coils to freeze up. On my car for example it was stuck on 26 degrees Celsius, even after a reflash of the latest software.

On my car we haven't completely ruled out it being a temp sensor failure vice an ECU problem, and the ECU problem doesn't totally make sense to me.....but I have an HVAC box on order as the sensor is non serviceable, the whole box has to be replaced. That is a front clam off job, 8+ hours. According to LCUSA this has just started popping up.

With my car, I just have to manually cycle the AC button on and off, so that it doesn't stay too cold for too long, as it still blows ice cold. Annoying, but at least it cools the car down until we get it fixed.

Invictus,
I sent your theory to my dealer for him to ponder. When I took my car to him last week, he could not replicate the condition even after one week. Now that winter is upon us, I will not be using the AC too frequently but I wanted to log this problem with the dealer because my warranty will expire in Feb 2014.

 

[Stephen Harper]

I am having this same exact issue, it appears to be an issue with the air diverter/flap. where is that located on the car, looking to see if I can pull it/repair/replace it?

This would be like a diverter in a house air duct? Where is it located in the Evora? That's what the malfunction feels like. Sometimes the AC is working fine, then suddenly the air flow shuts down to 10% of the flow. Same sound from the fan, just less air. Then, just as suddenly the air comes back full force.

 

[SuHong Kim]

I am having this same exact issue, it appears to be an issue with the air diverter/flap. where is that located on the car, looking to see if I can pull it/repair/replace it?

It's at worst possible place to replace. You have to replace the whole HVAC assembly which is located at the center of the front crash-structure. This means that u have to remove basically everything in the front clam, discharge AC (because you have to replace the whole assembly) and all. (To be more specific, its about 5inches in front of cabinet air filter, vertically below and horizontally between air-channel tunnel thingy and no, you can't reach it from below)

My recommendation is you might wanna disconnect and reconnect the HVAC wiring connector (and possibly put a electrical grease) which is located right below the washer fluid fill-up neck. You need to be acrobatic to do this, but I've seen this (myself included) fix the HVAC related issue.

To be specific, previous owner for my car reported an issue where blower fan stopped working and Lotus tech fixed it by reconnecting the wire. Under my ownership, blower fan stopped working and during research to fix this, I've talked to Evora S owner who repeatly had same issue. He told me that he fixed the issue by hard-wiring the connectors and never had same issue for 3~4 years. Now, I just put a electrical grease and I never had blower fan issue for 1.5 years.

I understand that your case is different than mine as your HVAC fan is partially working, but I think this is worth a shot.