Mode Door or Blend door?

LIFEX1

MEMBER
2013 NISSAN ALTIMA
3.5L
6 CYL
2WD
AUTOMATIC
125,000 MILES

I cannot switch my AC/heater to defrost or floor or to dash vents or to floor/defrost, etc. Air is moving, as I can hear it, I just don't know where its blowing. I knew this was going to eventually become an issue as my AC/Heater would work intermittently between those modes until today. I cannot get it to change modes. I can watch the actuator move when a different mode is selected which is why I am so confused as to what to replace. When it was working, I would get cold air when requested and heat when it was requested so I don't think my blend door is the issue. I am still getting just a bit of cold air now but the big majority of the cold air is going somewhere else. Is this a mode actuator that's bad or a blend door actuator that's bad? I've seen the blend door replacement diagrams/instructions but I have yet to see anyone with a mode door replacement diagrams/instructions.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

If you cannot move the position of the air then this is a mode door issue.

Here is a guide that will help with some info on this:

https://www.2carpros.com/articles/low-or-no-air-flow-from-vents

However, the confusing part is that the actuator is moving but more then likely the plastic gear is stripped so it is not moving the actual door. So the air direction does not actually change.

I would suggest starting with this issue as it can affect the temperature as well. However, we may have another issue but let's start with this and go from there. Thanks

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