Hi everyone. I'm brand new here, so bear with me. I just picked up an A2B 36 volt, 750 watt hub motor on a Craigslist deal for $50. I have the "switch" module. I've watched a lot of YouTube on Ebikes and have always seen that the throttle connection to the motor controller is a 3 wire connection. I'm looking at the connection on the A2B module, and it's 4 wire. I'm then looking at the wiring schematic in the A2B service manual an I'm seeing this fourth wire, both at the throttle and at the motor (the controller is inside the motor) That is a "grey" wire labeled "Eal". Does anyone know what this Eal wire is for? I'd appreciate any and all help! Thanks!