First thing get rid of the off delay relay. When it fails it drains your battery dead. Just unplug it it will not interfear with low or high speed fan operation.
From reviewing the drawing, the off delay relay could be causing your fan to be on, the high pressure AC switch could be stuck closed, the high temp switch on the intake could be stuck closed, any of the three relays could be stuck closed, or you have a ground signal to a relay coil that is shorted to ground causing the relay to close.
Unplug the off delay relay first and then test.
If still have problem unplug AC high pressure switch
If still have problem unplug one at a time high speed relay, then low speed relay. Findout which one is causing the fan to run then you can test further.
