Electrical Problem

[StreetLegal-ish3]

I have a 2000 Lexus GS400... About a month ago, my car decided to stop locking when i left my car. I would hit the button and the doors wouldnt lock. Then, when i got in the car and started it and tried to put any window down, my driver side buttons wouldnt work (or the lock button/or the window lock button). When i pull out of my garage my light guage doesnt turn off, when i put my seatbelt on, that light doesnt turn off. When i start my car, my dash take like 10 seconds to turn on. I took it to my mech, and he said i need a new switchboard? Does anyone know where i can find this? Or if that even is the problem?