A/C Leaking

[mickeydog]

Hello,I just noticed the passenger-side carpet is soaked so I called the dealer and they said the A/C drain underneath is probably plugged.Long story short that is not the problem,for some reason the condensation from the A/C is running back inside the car.Does anyone have any ideas what it could be?Thanks

[B Hoth]

Make sure that its not a bad heater core.

[C&C]

We may need the long story because what you describe is a plugged A/C drain. (the condensation from the evaporator does run to the drain) Now, it could be a leak in the evaporator collection pan (meaning the condensation never gets to the drain hose). And, as mentioned earlier, it could be the heater core leaking; though that would have a distinct smell of antifreeze.

[mickeydog]

Sorry I was in a hurry last night,I do not think it is the heater-core,the coolant level is at full and no coolant smell inside the car.The dealer told me it is rare for a heater-core to go bad,they do not even stock it.Thanks

[mickeydog]

Hello,I just took the bottom of the dash apart and the water is dripping from the control module.Is there a seal that could have went bad or can I remove it and seal it with something then see if the leak starts somewhere else.Thanks

[C&C]

Another tell-tale sign of a plugged drain line would be a slushing sound from around the same area you are experiencing the drip. In any event, good hunting; hope you fine the source soon.

[mickeydog]

It is really weird when I let the A/C run now it is not leaking from the control module but it is not dripping underneath the car either.I will take it to a mechanic friend of mine and let him figure it out.Thanks and Happy 4th of July I am going golfing now......

[mickeydog]

Please help,nobody so far can figure out why the A/C is leaking water inside the car.

[RightTurn]

Send a PM to EWILL3RD. He's a certified master Cadillac mechanic for Lindsay, and he will answer you.

[ewill3rd]

I think we spoke via PM, here is the bulletin I was talking about.
Not really a fun one but....

Condition/Concern:
Water leaking or wet carpet below the HVAC case on the passengers side.

Vehicles built after 5/28/02, VIN 30115764 have been corrected at the plant.

Recommendation/Instructions:
Perform the following steps.

Remove passenger door sill trim.
Peel back the passenger side carpet up to the passenger seat, keeping seat in car.
Detach rear passenger foot duct from heater and A/C module (HVAC) using flat screwdriver to unsnap lock tabs, or just twist and pull the duct.
Detach wire harness from rear duct at multiple points.
Pull rear heat duct forward and remove from vehicle.
To dry out HVAC module, place control panel in foot mode, a/c off, max hot, high blower, and run for about ten minutes.
Turn off the climate control panel
Wipe off bottom of HVAC module to dry off.
From driver’s side, wedge the handle end of a skinny screwdriver between the plastic drain end and rubber tunnel insulator mat, to hold down the insulator mat.
For surface preparation of the two HVAC case seams, sand the plastic seams and follow directions on sealer tube for cleaning procedure which includes using paint thinner so as to remove any release agents or surface contamination for good RTV adhesion.
Using a tongue depressor type of wooden stick, or a paint stirrer, apply ample silicone sealer 3M Part Number 08662 or GM part number 12346192 (squeeze tube) or 12346286 (caulk gun). About a 1/4" to 1/2" bead along entire bottom of HVAC case seam, creating a continuous seal from the front side to the rear side of the case. Any missed portion will become a new leak point.
After getting the silicone on the case, use your fingers to dab the silicone upwards tight to the case.
Using only your fingers, continue the silicone 1" up the rear of HVAC case to the first screw boss.
Continue the silicone 1"-2" up the front of the case.
Pay special attention applying silicone to the bottom front of the case passenger side where the seam is lower on the driver side than it is on the passenger side.
Allow silicone one hour to dry.
Run vehicle with a/c on for a half hour to check for water under the case.
Put the car back together, making certain that the right rear foot duct is fitted into the duct outlet trim piece under the passenger seat.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

Models:
03 Cadillac CTS