Well I would start with fuse/ relay. ( don’t know about relay)
His a bit from the manual I have .
“Blower
The blower is installed between the air inlets and the evaporator, and consists of 2 open hub, centrifugal fans powered by a single electric motor. Operation of the electric motor is controlled by the ATC module via the blower motor control module (voltage amplifier) installed in the outlet of the RH fan.
To produce the seven blower speeds the ATC module outputs a stepped control voltage between 0 and 8 V to the blower motor control module, which regulates a battery power feed from the central junction box (CJB) to the blower. The control voltage changes, in 1 V steps, between 2 V (blower speed 1) and 8 V (blower speed 7). If the control voltage is less than 2 V the blower is off.
Blower Motor Control Module”
Guess small looking digging needed.
J