996.2 electrical gremlins

Any help is much appreciated. I�ve been working on this for a few weeks without success. Bought an Auction 996.2 Cab and it showed up with a lot of water behind the seats. All interior lights are non-functional and the rear engine lid doesn�t work. The convertible top worked irregularly now it doesn�t work. Rear deck lid switch makes no noise. I measured a voltage at the solenoid by the engine activated by the switch but it wouldn�t pop the deck lid. I ordered a new one and it didn�t work either. Same with the interior lights, glove box light and door / trunk lights (license plate lights work). I measured power going to the dome light so I figured it was a bad dome light board or switch. Replaced the dome light assembly and nothing. Next I�ll try the ignition switch because key is kinda grabby and it says key is not removed even when it is. Read that can cause weird electrical issues. Any ideas on why I measure voltage to the latch solenoid and dome light but replacing them didn�t work? I�m pretty sure the alarm module under the seat got wet but everything else seems to work. Also getting a brake pad sensor warning which persists even after replacing all the sensors.

Quotes source post: 19421064

Well, to start with, if water was behind the seats, you at the least have to open up the immobilizer. on to your inoperative engine lid. Normally I'd tell you to check fuses, but you say voltage is already there... " I measured a voltage at the solenoid by the engine" ..? Not sure how you're measuring voltage and where, something is wrong here. lets at least determine the lid latch is good... Apply momentary 12v directly to the latch coil in the back of engine bay, you say the unit is new oem, the latch should work. You should hear it. Do not apply 12v to any micro switches. Report back, we'll go from there. jmo

I would get the ecu and immobilizer to dr ecu for evaluation. Likely has water damage and they can repair them.

ECUDoctors is the go to place for this type of problem. The need your DME/ECU, immobilizer and keys. https://www.ecudoctors.com/#

Quotes source post: 19421264

Lid latch solenoid works when I apply 12v directly the plunger pushes out. I retested with the multimeter and activation of the micro switch next to the driver seat only produces 3.5 mill volts at the solenoid. same with the dome light. Only 3.5 mV is available at the dome light switch and when I connect the dome light switch to 12 V it works.

All that stuff is controlled by the immobilizer/alarm unit which is under the driver's seat, and easily gets flooded out and damaged.

Quotes source post: 19421616

Just pulled it out and it�s seen better days

Call up ECU docs and they will go through everything. While you�re waiting for the ECU analysis, look for any corrosion on the wires, and check all your drains.

Thank you all for your advice. I�m going to see if I can clean it up on my own before I send it to ECU doctors. Lots of great online DIY for cleaning water damaged circuit boards. I�ll keep you posted

Quotes source post: 19421633

I see progress being made. Send all those modules that have been underwater off for a refurb. Best,

Cleaned up the immobilizer but the dome lights and rear deck solenoid still don�t work. Before I send it out for a $1500 repair I�m going to try a new ignition switch for $20 and maybe try and get the dealer to see if the software went into shipping mode because the battery was completely dead. Here are the before and after pictures of the immobilizer