Mercury 60 four stroke Motor reverse polarity on cranking batt with accessory wiring

[Austintxoutboard]

I installed a marine cranking battery and deep cycle and believe i reversed polarity with the accessory wiring that it is fused on the cranking battery when i caught myself, then corrected my mistake. looked aat the fuses didnt notice any blown as well as when key on fuel guage doesnt work shows the tach as if it was idling not running and doesnt crank. any advice to get this fixed. i dont know if their is a fusible link its a brand new motor rig. what needs to be done to turn over the motor and get the guages reading properly.