Everything just died
 

So I'm just cruising along at 3500 RPM on our way to dinner. Boat just went completely dead. Both motors. No power to any helm switches. Had been out all day and the previous day without a hiccup.

Spent 10 minutes attempting to diagnose before getting a tow back to the marina and walking her back on the trailer. Battery connections are all tight. A couple of items wired directly to the batteries still work. I'm thinking something in one of the battery switches? I did not pull the switches apart yet. Are there fuses in them? Not sure where to start. Maybe lost a major ground?

sounds like you lost ground. Each engine has a seperate power wire to the key for that engine.

circuit breaker on engines? may have a dead short somewhere..

There is generally a main in-line fuse going in to the ignition switch. If that blows you loose everything, gages, switches cranking, everything.

Large fuse that is in your starter. Looks like a little square attached to starter. Your alternator is hooked to it. When they fry it all goes out. Can't be reset you have to replace them. You can check by jump those wires to the hot from Batt.
Hope this helps.

Both engines?

Same question. Both engines?

The toilet flushes (electric macerator directly wired to battery). And the trim tabs work. That's it. Nothing else. I haven't tried putting in on shore power or anything so my house power may still work????

Kill switch........?

How many batteries and how many switches do you have? I agree that is could be the ground, but if you have a single battery or a single switch, your problem could be in either.

A friend just had this happen. twin 496 baja.

If it were the kill switch I would still have power at the helm.

Two switches, two batteries.

Mine only dopped one side at a time. You would have had to blow sb and port in line ignition fuses which seem improbable. Id check it none the less. It sounds more like the main perko battery switch at this point.

Open your seat where the two Perko switches are. About 3 inches above the switches there are breakers. You may have to put your head in there to see them. Typically the issue that caused mine was an issue with trim grounding out.

Yep happen all the time. Very easy to jump and check and be done with it. It is the first place to start and look if perks is on this is second source of power to everything. After that ground but highly un likely since there are multiple grounds.
Disconnect and hook straight to large post on starter thing should come back on. Then you know.
These are one of a couple things that can cause everything to go out.

The 50 AMP breaker on the ST side Mercathode popped. We tightened up a few loose wires, reset it and all seems well. If it does it again, there must be something we missed.