A band of electrical gremlins nested in my car
 

So after changing the clutch and generally making my car happy, I parked it overnight on the streets in SF and whaddya know. My car gets infested with electrical gremlins. I come out in the morning after it was raining all night to find the spoiler up, windows down and battery dead.

After a jump I was able to get home however going down the freeway my friend told me that my tail lights were blinking (lights were off), the reverse lights went on, and at one point the top tried to cycle open or closed. This is accompanied by warning beeps more or less constantly.

I make it home and try to put the battery on charge and my charger does not seem to want to charge it. So I figure that it may be Optima induced gremlins so out it goes and in went a brand new Bosch battery, No change...

I hooked up my Durametric and after some digging around it appears the rear control module is malfunctioning. At the moment I can't even open the rear trunk. Not with the key or the button.

So now I need to find out where the rear control module is located and whether or not its the module itself or a cut wire or what. Anyone have any experience or first things to check?

If it was raining all night with the windows down chances are good the brain box mounted on the floor under the seat may have gained moisture and is now compromised. Some guys have had luck drying them in the oven if it is indeed the CPU.

+1
the only control module you will find in the trunk, is the DME.

The only thing though is that it failed and decided to try to drop the top while the windows were originally closed. They were only down 2" and the interior was not overly wet. Area all the control modules located under the seat? All the errors I am seeing are CAN communications errors with the other modules.

Did you check under the seat for any moisture you can feel by hand? You stated the Durametric pointed you to the control module, that is where she lives, I'd still be looking there based on the codes; the failure could be what opened the windows to begin with. I would also think carefully about anything electrical you disturbed or disassembled when you did your repairs and look for any problems. Start with the module maybe you will get lucky and find a loose connection, it happens.

If the rear drain holes that are under the convertible top lid were plugged, water can find its way into the passenger compartment. Perhaps, this happened given the intensity of the storm in SF and triggered a failure in the module that's under the seat, which led in turn to the windows opening etc.

The car is no stranger to water and in the past I have never seen any moisture collecting under the seat. I usually end up fishing around for change or a hat or whatnot. It is possible that this time something has ended up clogging the drains and flooding the unit.

I'll start pulling it apart tonight and see if there is water damage.

Agreed. Pull the driver seat and see if the alarm module took a bath. If it is wet you can sometimes remove it, open it up and use a hair dryer on low heat to dry it out thoroughly.

Other drivers with similar problems:
http://www.renntech.org/forums/topic/38278-what-control-unit-is-under-drivers-seat-2005-997s/
Alarm Control Unit Disaster - 986 Series (Boxster, Boxster S) - RennTech.org Forums

You guys nailed it... this time i did have a wet floor and a soggy box. I'm giving it a good once over and will give it a shot. If it works I will be quite happy. If not I am water-proofing the new one that goes in. Not looking for a repeat.