2008 Z21 strange electrical happenings

[nickrogers83]

I finally got my Z21 out on the water after installing my newly rebuilt powerhead (HPDI doing HPDI things). Everything was good and I was cruising mid-range, went to adjust my jack plate, and it wouldn’t work. No worries, kept going, adjusted my trim a little, and suddenly everything stopped. Engine, dash, etc. Just went black. When I punched the code and tried to restart, there was nothing. I flipped the breaker off and then back on again, and everything fired right up. I fished a little while, ran back down river to another spot, shut down, fished awhile, then had to trim up when my motor hung on a laydown. I had my radio on, and noticed when I hit the trim, my radio would quit, then come back on. I elected to shut that down. Quite the head scratcher. I fished for a couple more hours, then fired up and idled about 10 minutes to let the engine warm up again, then got up on and plane and again cruised mid-range. Jack plate and trim were working just fine. I got near the ramp and started trimming down when the whole ride went dark again. This time, when I would punch the code and hit the start button, the keypad would shut down. I reset the breaker again, and no change. My trim wouldn’t work, and this was including the trim button on the engine itself, but oddly enough, if I turned the keypad on and sent power to the bow panel, the bow trim buttons would work. At the ramp, I did find my hot accessory post was slightly loose which fixed the Power Poles not getting power as well as the jack plate. It did NOT fix the other issue of not starting, and I noticed that even my electric fuel pump (I did the Holley conversion last year) was also not kicking on. Everything else on the keypad works fine with no issues, but even after disconnecting and reconnecting everything at the battery and even trying a booster just in case my battery went bad, the fuel pump does not kick on, nor does the motor turn over (not even a click). I did also notice that my 1/2 fuel gauge selector light is blinking. I tried the “hold to reset” procedure, and nothing there. I’m at a loss as to why the blinker and engine trim switch don’t work, but my bow panel trim switch does. Hopefully I can do some further wire wiggling under the dash tomorrow evening, but I’m honestly at a loss as to where exactly I should start. Any advice is appreciated.
BTW the engine runs great - many thanks to Chris Carson for the rebuild.

[champ223]

Maybe check all your ground wires. On the engine and the battery compartment.

[kelbro]

Check the kill switch for loose or corroded fittings.

[rangered]

I would also check your keypad and brain connections. Take off the positive cable on your cranking battery and one at
a time pull off the connectors. Put them back on and push them on real hard. Once all this is done install cable back on
battery. Also I would install a Shutoff switch along with the breaker that kills off power. I don't think it's good to have
the battery charger going thru the keypad and electronics. Good Luck

[nickrogers83]

I would also check your keypad and brain connections. Take off the positive cable on your cranking battery and one at
a time pull off the connectors. Put them back on and push them on real hard. Once all this is done install cable back on
battery. Also I would install a Shutoff switch along with the breaker that kills off power. I don't think it's good to have
the battery charger going thru the keypad and electronics. Good Luck

I did disturb some wiring underneath the console when I rerouted my Garmin wiring (it’s all on a separate harness and power source). I’ll start there and check all my grounds on the motor itself too since I just had a rebuild and all of those things disconnected for that. The power to the brain/keypad is on a 30a switchable breaker, and I keep it shut off when I’m not on the water so nothing gets past that when I’m charging.

[nickrogers83]

UPDATE: After a few minutes of troubleshooting, I checked the trim fuse under the cowling and it was burned out. Replaced it, and everything works beautifully now! The trim switch on the bow accessory panel must be wired to bypass the main trim circuit (it would still be circuit protected on its own since it passes through the key pad though). No error lights blinking, remote fuel pump kicks on, and no blinking out on the radio when I hit the blinker trim. I think the fuse was probably on its way out, and that last run finally did it in. Still pretty weird losing that shuts the whole system off on you while you’re running, but it’s the only thing that makes sense considering both shutdowns happened when I was trimming down to start coming off plane.