Ac drain where does it goes?

Today i run the ac for a while. It works good :slight_smile: … but differently from my honda i didn’t noticed water draining on the garage pavement. I have no wet carpets whatsoever so where does the ac drain?

Down inside the center console and out the bottom. They do get plugged and will damage the AC system when they stay full of water and will drain onto other components and damage them.
When I had a shop and we serviced these cars regularly, checking and clearing the drains was on every major service.

Andrea …

Just a thought, remember humidity has a huge effect on how well the a/c system works.

If the humidity is low the system doesn’t have to dehumidify (remove the water) the air so in that case you won’t have any water coming out of the two drains. High humidity and there should be a good bit of water coming out when the engine is turned off.

If your A/C drain tubes are blocked (they usually do from time to time), pull back the carpet on either side of the transmission tunnel far enough back that you can see the drain tube connector. It’s a black rubber tube about 4cm long connecting two clear tubes; the top one heads up to the evaporator cavity and the lower one out to the bottom of the car.
Inside the heater core, 30 odd years have taken a heavy toll on the foam and the crumbled remains fall to the lowest point, which in this case is right around the evaporator drain holes.
Unless you’re going to dismantle the heater unit, (massive job) you’ll have to clear the A/C drains from time to time to prevent condensate building up and eventually getting into the blowers, frying the speed controls etc etc.

The way I maintain my car is by disconnecting the lower drain tube and temporarily replacing it with a length of clear tubing of the same diameter - much longer though, long enough to go along the footwell and out of the front door. Once the tubing is out of the door, attach an air line or can of compressed air to the end and give it a couple of blasts. That will clear the blockage and water will drain right away. This is the reason you put the hose outside the car door. After draining, reconnect the lower hose.

To get rid of some of the foam debris, you can remove the big fat square hose leading from the blower to the heater and pass a thin vacuum cleaner hose into the heater drain area below and around the evaporator. Sometimes you can clear out quite a bit of old foam crap that way.

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Excellent advice, Larry. An ounce of prevention is worth a pound of cure, right?

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i will check if with a lot of humidity i see the water dropping. I don’t’ see any sign of wet carpets or any smell of standing water. And do asap a clean of the drain tubes.

Gents …

Since I don’t believe many people have actually removed the evaporator and separated it from it’s housing, here’s what I found when I did …

When new there was a thin black foam sheet attached to the front of the evaporator. My guess is to prevent debris getting to the cooling fins. Also a thicker piece of foam was wrapped completely around the sides of the evaporator to seal it inside the housing.
Screenshot 2024-05-13 at 11.23.07 AM

Over time this foam breaks down and turns into a sticky mess which actually clogs up the evaporator … Really poor design, I had to soak my evaporator in a bucket of cleaner overnight to remove it all. I replaced the foam around the sides of the evap with rigid styrofoam.

(Sketch incorrectly shows two drain hoses, there is actually only one)

The bottom of the housing has two channels molded into it to collect the water coming off the evaporator. There is one drain at the low point that both channels drain into. A thin perforated metal plate covers each channel. (sorry about the poor quality sketch)


88-92 US Spec cars have #2 & #3. 93-94 have two #4.
acDrains.pdf (67.7 KB)

my 89 40 is on the passenger side footwell by the tunnel, there is a fitting I can unhook and clear. pull the carpet front towards the back till you see it.

Gents …

Here’s a picture I found online of the back of the assembly showing the single drain.