How to address water leaks, wet floors and restore wet under seat controllers.

There are really only three causes of a wet floor in a 993:

• The drain to the AC Evaporator chamber is clogged and condensation or even rain from the hood vent is backing up and spilling over into the cabin. Here is a page with a note on how to test the evaporator drains.
• The channel around the windshield or back glass has become rusted to the point where the bottom of the channel has rust perforation allowing water into the body. Here is a page on how to seal up the channel and forestall if not eliminate an expensive and invasive Bodyshop repair.
• The sunroof drains are clogged and rainwater is backing up and running down between the cabin roof and its liner to the floor. How to address this is outlined below: 
• Note the section at the end of this document on how to dry out water-soaked footwells and address/salvage/restore any under-seat controllers, DME, Immobilizer, alarm, that got wet.

The dead giveaway that clogged sunroof drains is the source of the leak is that when one peels back the inside surround along the top edge of the windshield it will be wet.

The remedy is rather straightforward. Make a plumbing snake out of a section of 12 gauge insulated solid-core primary electrical wire dulling the end so it does not puncture the drain tubes. The wire is easily purchased by the foot at most home improvement or hardware stores.

Open the engine lid. Under it on the top left and right corners you will observe the sunroof gutter drain outlets in the body sheet metal behind the lid hinges in the picture below:

Use the snake, gently slipping it up the drain outlet tubes to clear any clogs from the tubes. Be gentle and do not use a high level of force if the snake hangs up a little back it out and try again possibly with the end bent in a slightly different direction as the goal in this is to not damage the drain or its terminations.

To test the drains close the sunroof and with a slightly flowing garden hose wet down the sunroof seams and observe the broken free debris and water emanating from the two drains.

An alternative process could be to use a little compressed air at the drain outlets to blow any debris obstructing the top end of the drain tubes seeing that the top ends are not so easy to get to without some disassembly of the roof panel. Be sure to not use too much pressure as one doesn't want to blow the tubes free of their top-end moorings.  If you take this approach you may want to consider protecting the open roof from splatter and find any solid debris that is forced out the drain entrances so it doesn't just flow back into the drains.

Once the drains appear to be cleared leave the vehicle out in the sun with the sunroof partially open to bake any moisture trapped in the headliner out of the cabin and mop up the floors. This may include pulling back the carpet in the footwells and removing the floor pan soundproofing foam rubber inserts, laying them out in the sun to bake dry. To remove the inserts minimizing damaging their black rubber laminated top consider cutting them loose around the edges using a razor utility knife. Once dry they can be dropped back into place as is.

How to dry out water-soaked footwell and address any under seat controllers that got wet:

• Pull up the carpet
• Using a utility knife neatly cut the black rubber floor pad around the preifery of the footwell
• Lift the molded floor pad out of the car and leave things open to dry.
• Once dry reinstall the floor pad in position and reinstall the carpet.
• If you are concerned that any of the controllers or audio components under the seat got wet and before having them repaired consider the following procedure to restore them first:
• Disconnected the car's battery before starting the below steps
• Here is a page on how to remove the seats to gain access to the controllers.
• If a security cover is present, drill out the security rivets on the cover over the controllers under the seat.
• Use a shop vacuum to clean out the metal shards left from drilling before unplugging the controller to avoid contaminating the electrical connections.
• Unplug and open up any controllers including the DME that got wet and blow-dry their guts out with a hairdryer. Also,
• Blow-dry any connectors to them.
• Use some spray electronic cleaner to hose off the last bit of moisture and contaminants from the boards and connectors once they appear dry.
• If you are handy with a soldering iron this is a good time to inspect the boards for cold or oxidized solder joints or traces and reheat or tin them as appropriate.
• One can also consider the remote keyfob receiver upgrade discussed on this page.
• Close up and reinstall the controllers
• Replace the shield cover if present when finished with some self-tapping machine screws as it may be providing some required electrical shielding.

Fogged dash gauges:

Some have experienced fogged dash gauges on the inside of the gauge glass and attribute this to excess humidity in the cabin from a water leak. I have been unable to corroborate this as the root cause but it is something to keep in mind as a potential early warning of a water leak that should be investigated.

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