Battery fan speed tied to vehicle speed

Hey all,

I've had no trouble codes, but realized my battery temp was high when using Dr. Prius. Realizing I've never heard the fan run, I checked and found the corroded plug in the trunk, cleaned it and the fan ran - but now its running at a speed seemingly directly tied to the inertia of the car! Not exactly wheel speed, but wheel speed +/- acceleration.

I'm assuming the resister is bad, but I'm hoping someone can help me diagnose the circuit. I have a multimeter but don't know how to read the wiring diagrams, and I believe there is a fuse, a relay, and a controller on the same circuit. But I don't know to determine if the control signal from the ECU is bad as well.

Any help is appreciated! Gonna see if I can capture a video later.