2014 Mercury 60 four stroke Motor reverse polarity on cranking batt

[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.

 

[Texasmark]

On alternator equipped engines, you usually have rectifier diodes since you need direct current (dc) and alternators are alternating current (ac). 1 or 3 (depending on the engine application) are on the positive output side and 1 or 3 are connected to ground. If you reverse the battery leads you put 12 v on the anode of the grounded diode(s) and something like infinite current flows through it/them burning them up. Find your rectifier/regulator module and replace it. To identify it (at least on 2 stroke engines) 2 yellow leads come from under the flywheel for power input and a couple of red and black for 12v output and ground. The grey wire is your tach signal.

Mark