I answered your PM but it is hard to trouble shoot such things via internet. One thing I did not mention is do not confuse the relay power wires with the motor power wires. Put 12 to 24 volts across the relay power wires and you should see your meter indicate voltage to the motor power wires--disconnect the motor power wires from the motor for this test.
Do not operate motor out of water. Keep fingles out of prop. Operating the motor out of the water can damage the seals and cause the shaft assembly to leak. The manual says no more than 10 seconds.
I mentioned and I will again, it is probably best to disconnect the light and dual the switches to the motor. The light is a known issue with igniting hydrogen gas in the housing--kaboom! Yeah, yeah, I still have my light connected but the one I sold I disconnected for their safety.
Look up at the charging jack, make sure there is a phenolic isolator from the diode to the metal bracket---you do not want a short here. The purpose of that diode as I understand it is to prevent sparking when the charger is connected causing yet another potential hydrogen explosion.
Relays can go bad but somehow I doubt it.
edit to clarify.
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