i recently installed a new ignition switch from on my Mercury efi 225. This weekend I was fishing at fork and everything was working just fine. Sat night, I was done fishing and was going to head to the ramp. My motor would not turn what so ever. The kill switch was not the issue. Also, the trim at my throttle would not work. My battery was good because all my electronics were working. Next day, everything worked. Motor started up/turned over with absolutely no issues. Problem I have now is trying to figure out what was causing my ignition not to turn over. I have a bass cat boat and not sure if they still have the older wiring schematics. Anyone ever had this issue or know where to begin. Thank you for any help

check ALL grounds, especially tha battery and motor. clean and reattach battery cables (regular nuts, no wing nuts) at both ends (motor and batt).. if trim doesn't work that indicates battery circuit and/or power to tha switches/trim motor.. loss of power to tha switches is gonna be battery circuit or trim fuse.. that fuse will not effect starting though..clean/check ALL connections on tha solenoid (big, little, power and grounds)

You might try the remote harness plug in the motor. Make sure it is clean a s well.

I ran into a problem with mine a few times where it wouldn't start. Turned out to be the starter gear was hanging up in the flywheel. The gear had a few rough edges on it that would hang up and not let the gear disegage. I put some grease on it and it helped but would occasionally hang up.
If I tried to start it and I had power but nothing would happen when I turned the key, I would put the motor in gear, raise the motor, then take my paddle and rock the prop back and forth a little. This would pop the gear loose from the flywheel. Put it back in neutral and it would start right up.

just my experience with mine...

Thanks for the information. Everything seems to be working just fine now. Checked the motor wire and console wiring and did not find anything. I'm sure it will quit working on me at the worst possible time. Lol

jus for grins check all tha positive connections at tha solenoid.. power to tha key switch and tha control handle trim switch come from a separate small red wire that attaches to tha big positive terminal (positive battery connection) on tha solenoid thru tha harness... like Tommy said check and clean tha male and female harness connectors at tha motor....