Hello everyone this is my first post because I cannot seem to chase down the source of this electrical problem. 2004 D2, 140,000 miles and I have owned it for 3 years now. The problem started in november 2019.

I have an electrical problem that seems to occur with humidity and rain / snow. When the car gets wet or there is heavy rain outside (problem starts before I pull out of the garage) my winshield wipers, radio and seat heaters stop working. The loss of the wipers is escecially inconvient. When pressed on the seat heaters buzz loudly when the issue is occcuring. I often won't notice until I use the swipe function on the windshield and the radio dies and the wipers get stuck in the middle of the winshield. The only way that I have been able to tolerate it is because setting the wipers into high speed mode seems to jolt everything back into working again. After that, it usually lasts for anywhere from 5 minutes to the next day of working properly (depending on the weather).

I have tried the following: inspected all the connectors in the passenger footwell for corrosion, swapped the passenger compartment fuse box, swapped all related relays for new ones, and cleaned every single ground point that I can find. Any suggested next steps?

Thanks!