Dirty cabin filter installed backwards broke air conditioning?

[sven337]

Hi,
while I was doing something else on the car, I figured I would check if the cabin air filter needed to be replaced. It did, and until I could get the new one I reinstalled the dirty one (after having shaken it a few times outside to kick off as much crap as possible). Unfortunately, I installed it backwards, and I suspect it may have broken my air conditioning.

I wasn't in the car when it happened, and the person driving wasn't very technical - what they told me was that as soon as they turned on AC ("normal" ventilation worked fine), they saw "white smoke" come into the car. That smoke was apparently odorless, and stopped after a few seconds. When asked, they said they had no idea whether it could be condensation or real smoke.

Since then, the AC still works (without any white smoke), as you can feel cold air being blown inside the car, but it definitely doesn't work as well as it used to - the air is cold, while it used to be *very* (exceedingly) cold. With summer being on us soon, I'd like to have AC that works well.

I assume that some of the particles stuck in the filter were sucked into the system where they caused *something*. Any idea as to what that something may be, and how I can fix it?

Thank you

[dogsridewith]

Was the removed backwards-installed filter element intact? Check for blocking inside the HVAC drain tube.

[sven337]

The filter was intact, but dirty.
Can you help me find the HVAC drain tube?
Thanks
EDIT: I should do my homework first. https://www.youtube.com/watch?v=AmeQiOrHFug and a multitude of results come up. I'll try that and report back.
EDIT2: The HVAC drain tube was not clogged. I ran the AC for a while, cut the engine, and didn't see anything come out though, so maybe there's a clog somewhere else in the system. Suggestions welcome.

[CoryM]

There isn't much damage the backward air filter could cause. Worse case it may have let more grit get into moving parts such as your fan bearings etc. These are designed to run w/o a cab filter, so you likely didn't damage anything.
The white smoke may have been dust from them using the fan in recirc for the first time and blowing the dust out of the backwards filter?

A/C refrigerant has dye in it and smells pretty strong so I doubt that is what they noticed. And the A/C wouldn't work at all now if the gas came out. Is it possible your A/C wasn't working well prior to the "smoke", and you just noticed now because your attention was drawn to it? Also, with the A/C and engine on, look underhood and see if the A/C compressor is actually engaged and spinning.

[sven337]

It is possible that A/C wasn't working too well and that the "smoke" just draw attention to it. That happens often in life. :)
I read, somewhere on this forum, the suggestion of running the blower at full speed with A/C and the vents closed. I did that for a while after having trying to unclog the drain tube (which I don't think was clogged).
It looks like that operation did recover some A/C "performance". It's still not blowing air as cold as it used to, but it can be considered functional. I guess a 10 year old A/C unit that hasn't undergone any maintenance/replacement can plausibly not perform as well as a brand new one.