Electrical problem

[blues midnight]

Had a scary incident today on the , just powering along but gps kept losing power, kept turning it back on, then holy crap, it started smoking! Got the wife to turn off the fuse switch and disconnected it then and there but then on way back the 90 HP Etec tach gauge would lose power and reset, especially when I changed speed. Now when I try to start the motor the power dies upon ignition but can be reset by reconnecting the battery. I still have power, no fuses blown, but power dies when I try to start the motor, battery seems ok. I know I need to start checking all the electrical connections on the boat and especially in the pedestal but any info or help in pointing me in the right direction would be appreciated.

[kmclemore]

Hmm.... I'm suspecting a bad ground to the motor... potentially the GPS and the tach failed because the power was back-feeding through them to ground.

[blues midnight]

Thanks, will start with checking the motor ground.

[Retcoastie]

Absolutely. You appear to have an open or high resistance connection somewhere, most likely in the ground side of the circuits.

Good luck.

[blues midnight]

Think I got it solved. Thank you for calling attention to a grounding issue.

Battery is wired for two via a 1-2-off switch, but I'm only using one. Neg cable to non-existent second battery was just dangling loose but still connected to neg terminal on existing battery so must have been grounding out. Took it off (seems like a lot of wing nuts are being used so will replace with lock nuts) as well as the unused pos cable and things seem fixed, motor starts, gps works, amazingly even after smoking, tho haven't tried it with motor running yet, will try first on the trailer before venturing on the water again. Not sure why gps would be affected by this to the degree of almost catching on fire, motor is wired direct and gps on aux circuit. My first serious problem whilst underway (and with all 4 of my daughters on board!) and also my first foray into boat electronics, scary...

[Jimmyt]

As kmc and retcoastie suggested, it sounds more like an open, or bad ground, than a short. Do you recall what position the battery switch was in when you had the issue?

To smoke the gps, it seems that you made it part of a high current circuit, also indicating that your gps fuse is too large, since it probably should have blown before smoking. Shorting the battery cables doesn't explain the gps smoke to me, but I didn't stay in a holiday inn last night.

Maybe one of the smart guys has seen this and can offer you an explanation. I would keep checking for a bad ground between the battery and engine - possibly intermittent. When you think you have it fixed, turn the steering and run the tilt to check for a bad connection or broken wire that only shows up when you get things just so.

You are very lucky that the gps will still light up. Usually when you let the smoke out of a device it ceases to function.

By the way, you corrected a very serious condition of having dangling battery connections loose in the battery area - particularly if you had your switch in the "all" position. Those cables will stay together through a max discharge of the battery, so leaving them where they can short is really risky.

I've only got three daughters, so you win. Wouldn't want a boat fire with them on board either (or at all for that matter). Good luck and keep us posted.

[Wind Chime]

Think I got it solved. Thank you for calling attention to a grounding issue.

..... Not sure why gps would be affected by this to the degree of almost catching on fire, motor is wired direct and gps on aux circuit. My first serious problem whilst underway (and with all 4 of my daughters on board!) and also my first foray into boat electronics, scary...

May be a good time to doublecheck your fire prevention tools on board.

Fire extinguishers.
Where we live, two units onboard are mandatory.
- One for the galley.
- One for the engine.

So in theory, one should be down below with easy access to the gallery, and a second should be near cockpit with easy access to the engine and fuel tanks.

Cross my fingers, we've never had a fire on board or even smoke (besides my cooking)