You were correct about this there was corrosion on the larger fuses and relays.The compressor wiring from the climate controller module ( the module with the display in your center dash) first goes to the relay module at the passenger side under the hood (where fuse 20 is), and is cross connected there and then goes to the compressor. In other words, it is not a direct wiring. So the wooden block on the relay module is to press on a a loose and maybe corroded connector that goes to the relay module which kept the connection going. So any bump loosened the connector disconnecting he compressor wiring. You need to take a close look at the connectors to the relay module (maybe a mechanic can do it for you) and make sure there are no corroded connector (usually due to water intrusion from the channel between the hood and the fender especially if the module lid is not properly installed. The same story with fuse 20 which should be 30 amps anyway.
The fuse 20 may be blown. Visually check it and measure power on both sides of the fuse (the tabs on each side). The fan is not powered by fuse 20. This fuse powers the fan control module which then powers the fan with different duty cycles (pulsed) to control speed. The fan may have power on it but not ground. Else it would have worked, right ? The power may be coming from some other power source that goes to the control module (only when the key is in position 2 (run). You need to make sure that fuse 20 is powered and not blown. Then you can take the next steps.
Make sure that the compressor is well grounded.