Electric Bikes - Brushless motor is always full on

I have a front wheel 36v 500w brushless motor. When I got the kit, it worked fine but now when I turn it on, the motor starts to spin at full throttle. I tested the throttle control and it is working like it should. I used a volt meter and tested across the black and blue cables while increasing throttle speed and the voltmeter goes from a little over 1 volt to almost 4 volts. I think that is correct.

I also took the controller apart and it looks and smells ok. I found a post on how to test the hall sensors and they work as the post suggested. I plugged in the 5 wire plug to the hub without having the 3 power wires connected and tested the black to red wires which read 5 volts. Then I tested from the red wire to each hall wire while turning the hub slowly and each wire bounced between 0 and 4 volts so the hall sensors in the hub look ok.

I suspect the controller is bad but I would like to know if there are any other troubleshooting techniques I can use to confirm the controller as defective. Please let me know if there is something else I can check. I am new to these brushless motors and am just starting to understand how they work.

I've had that problem before, and for me the problem was that the black (ground) wire from the throttle to the controller was not making a good connection... *I would check that first.. (run a new wire from throttle to controller)