Wet passenger floor from A/C

Bmachine

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Darn it. Just before I leave for a long trip I noticed that when I run my air conditioning on full blast I end up with a wet passenger floor. I did a search on the forum but, strangely I could not find anything even though I vaguely remember reading something about this a while back.

Since it hasn’t rained here for a long time and I have not washed the car, I am fairly confident that this wetness must be coming from the air conditioning. But when I look up towards the evaporator I cannot see any kind of source for this wetness. I know there is supposed to be a drain for the condensation someplace and I do see clear water on the parking area after the car has sat for a bit. But where Is the clogged drain that would cause the passenger floor to get soaked?
 

jmackro

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But where Is the clogged drain that would cause the passenger floor to get soaked?
Bo:

There is a drain at the bottom of the heater box, toward the center of the car. If that becomes clogged, the box fills with water until the depth reaches the air outlets - then it will slosh out as you go around turns. Once when mine clogged, I could hear the fan blades chopping the water.

Perhaps putting the car on a lift and using a wire to clear the drain would work. I added a back-up drain by drilling a hole in the bottom/side of the box, securing a tube into it, and routing it down the driveshaft tunnel and through the floor.

Well, the good news is that your A/C is working!
 

Bmachine

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Thank you, Jay. Yes I completely renewed everything on the AC system in the engine bay. Compressor condenser etc. But I haven’t touched anything on the inside of the car. So everything works reasonably well, except for this drainage issue.

I don’t suppose there is a way to clear this drain from the inside of the car is there?
I don’t think I will have access to a lift before my trip on Friday. Is there a temp measure that I can use just for this trip? Because now it almost seems like the water is seeping under the original sound deadening stuff that is glued to the transmission tunnel and passenger floor. I’m not seeing an easy way to capture it.
 

Stevehose

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The drain is directly above the transmission on the tunnel. You might be able to access it with a coat hanger if you can crawl underneath far enough or jack up one side. Not sure if you can access it from the inside, perhaps if you pull the radio to see. The seal around the hole may be damaged/missing allowing water to drain into the cabin instead of out the tunnel so it may not actually be clogged, I glued a small tube into the evap drain hole and ran it directly out the bottom to avoid this junction.
 
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jmackro

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The seal around the hole my be damaged/missing allowing water to drain into the cabin instead of out the tunnel so it may not actually be clogged....
I like that theory, as it explains why Bo is getting both a wet floor and a puddle under the car.

Bmachine said:
I don’t suppose there is a way to clear this drain from the inside of the car is there?
I don’t think I will have access to a lift before my trip on Friday. Is there a temp measure that I can use just for this trip?
Sorry, but if it's a leaking seal as Steve suggests, I can't think of an easy way to renew the seal.
 
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Ohmess

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I installed another drain on the passenger side of my heater box. At the time, I had access to another heater box so as to determine precisely where to drill. I believe it was toward the bottom of the box close to the firewall and about half an inch from the bottom and side walls, but please check this before you drill else you may ruin your heater box.

I used a drill stop because the drill bit must not go in too far or you may damage the evaporator. I then tapped the hole (well, started to tap the hole - I could only run the tap in part way) to match the thread on a small pvc elbow, and installed the pvc elbow with some gasket sealer.

I don't recall the size of the elbow, but it does not need to be very big. Moreover, the elbow needs to be short enough so that it does not hit the side panel when you put the panel back on.

I then drilled a hole in the transmission tunnel and pressed about a three inch piece of hose through the hole so that it stuck out under the car at least an inch, and connected the hose to the elbow joint using gasket sealer on the elbow joint. I have not had moisture in my carpet since I did this last year.
 
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