Fuse 21 blows constantly

AllData does not tell me which fuse is fuse #21, so which one is it? Once I know that I will be able to look and see what is on that circuit.

Yeah that helps a lot actually. I have had this problem before on a Lexus ES300 (Same thing as the V6 Camry). Same exact fuse. Turned out to be that a mouse had chewed up the wiring to the vehicle speed sensor. As soon as you turned the key on, it would blow the fuse. I will do some digging to try and get you wiring diagrams. As I recall, my diagnostic process was to pull the instrument cluster and disconnect two of the three connectors, and then turn the key on. I knew that if I kept doing that, eventually I would figure out which connector had the problematic circuit. I looked at the wiring diagram to see what was hooked up there, and saw the speed sensor, among other things. I raised the hood and looked down to the transmission and immediately saw the problem. An old rat's nest next to torn up wiring for the speed sensor.

Here are the diagrams. I will help to interpret them later this evening. My two year old just woke up.