What's up!?

Short: Simply put, it is a 2010 convertible with about 77k miles that when it gets rain has major issues with pretty much all interior/passenger compartment electronics, but external functions (lighting, engine) are okay. And then after it seemingly dries off, it returns to relative normalcy and everything works fine. What do you think?

Long: I have a 2010 Convertible, 6 speed manual with about 77k miles. I bought the car with about 60k miles in March of 2021. Based on the carfax I got when I bought it, there were two previous owners. Everything has been relatively fine, the car runs, the primary lights and accessory lights work, radio, windows, AC, heat, cruise control & the other steering wheel controls, and of course the sunroof and top close/open/up/down with little issue. Simply put, everything is good. That is until it rains. Almost every time it rains none of the interior electronics work properly, as if they are having a seizure or stroke. However, the engine runs, albeit a little rough, and the exterior lights work (headlights, taillights, high beams, blinkers) all work. I am not sure about the power side mirrors, I guess I have never tested them during the malfunctioning. As for the interior stuff, the instrument cluster can swing on and off, the radio/media console & speakers are the same, as well as the overhead lights & switches, the windows, too. I never tested out the sunroof and top, since it would be raining/wet. Once the rain stops, and things seemingly dry (which can take a couple hours or a day or two depending on how much rain, I guess), everything goes pretty much back to being alright.

Now when this issue first arose for me, it was quite the scare. I looked up lemon laws in my state and did research about causes and fixes. I never came up with anything solid, and since the car seemed to sort itself out and I could still realistically drive it when it rained, I did nothing. Unfortunately, last week on Friday after some normal rain a new, connected problem arose. I drove the car in the rainy morning to work about 10 miles away, with the expected hindrances, and parked up in a parking deck/garage as I have done multiple times before. Then about 5.5-6 hours later I return and get in. The car is still wet and giving the electrical gremlins, which is not unexpected, so whatever. I do not specifically remember if i started it up, or I only put it into accessory mode, either way I had forgotten something, so I disengaged the key fob and left for a few minutes. When I return, everything is normal enough, except there is a whirring/electrical sound from the driver's side rear corner. I do not recall exactly my steps here, but I know I started the car up to see if that changed anything, but no. I also went around to the tailgate and opened everything up to get a look, at what I afterwards realized was the convertible top pump/motor, and saw what was being problematic. I went back and forth between checking the rear and playing around with starting the car/turning it off a couple of times. After a minute or two I went to try and disconnect the battery, but that was a loss as I did not have any tools with me to do so. At some point, the pump/motor started to smoke. Seeing as there was not much for me to do, I thought to get ahead of a potential fire and called 911. By the time firefighters arrived, the pump/motor seemed to have stopped/died. There was still some smoking from the area, so they disconnected the battery and then gave the problem area a spray with an extinguisher. I eventually got a tow home at night and let it sit under a cover until Sunday afternoon. After some mediocre research, I figured which fuse to pull for the top and sunroof. Then I reconnected the battery and started up the car, with little issues, other than the date/time being reset. I also put the fuse back in to test the top functions. The sunroof and windows opened and closed just fine. The "A-pillar" (?) roof latches disengage and reengage, but no other full top movement.

So that is where it is at now. I reckon I will most definitely have to replace the pump and/or some wiring, but I will try to test/fix before that. More important than that, though, I should figure what is causing the electrical disturbances. This I do not really concretely know where to start. I would guess in one of the footwells, with either the passenger side fuse box or the more likely culprit in the driver's, the FRM. But if it is the FRM, I would be confused as to why it is only the interior stuff and not also the external lights.

Anyways, thanks for reading, maybe? Any help or ideas are appreciated.

 

Pretty much as soon as I posted this thread, I saw two very similar problem/description in the related topics, so I guess I did not research well enough.

• This thread seems the most similar to anything I have come across, so gives some promise of a solution. Electrical gremlins when it rains - North American Motoring
• A second thread, also quite similar. Possessed Gauges! (Intermittent Electrical Issue) Please help! - North American Motoring