Ignition switch inop after mis-wiring oil px gauge

[jg5343]

Ok, so here is an odd one for you. Boat has run great for 3 weeks, with zero electrical issues ever. Gauges were worn so we decided to replace them. Wife was wiring the new oil px gauge back together and accidentally crossed wires. It should have two ground (black) on the center post, and two positive (purple) on the batt post. She instead somehow put one of each on each post. When we went to op test the gauges she mentioned she might have put the wires on backwards and couldn't remember where they were originally. Assuming she didn't cross the colors without looking at them, I started the engine just to see an oil rise or not. There was an immediate rise on the gauge so I shut the engine off. HERE'S WHERE IT GOES SOUTH! The engine would NOT turn off! The key was literally off and removed from the ignition! Still running. I panicked because I had not planned on running the engine longer than 5 seconds, and was no where near water. I finally got the thing to shut off by shorting the positive and negative posts on the back of the oil gauge. Whew!

HOWEVER, now, after discovering her error, and correcting it, the key does nothing. Normally you get beeps after the key is turned on....nothing. Key turned to start does nothing. Found a 2A fuse blown, replaced that. All other visible/easy to see CBs and fuses are good. Still won't turn on. All the power on the panel including backlights, horn, wiper, nav lights, etc, all work perfect. Including the backlight for the oil px gauge.

WHAT DID I FRY????? Thanks in advance for the help.

Volvo Penta 8.1L GI on a 2006 2765 Regal Commodore

 

[alldodge]

I finally got the thing to shut off by shorting the positive and negative posts on the back of the oil gauge

You , blew the 20 amp ignition fuse

Also burned up the impeller running without water

 

[jg5343]

Impeller, check. I'll never turn the engine over again without water. This was eye opening.

Are you aware of where this fuse is located? I searched the obvious spots and only found a blown 250V/2A inline fuse. Replaced that with no luck. Thank you for your reply.

Also, any insight into why the damn thing wouldn't shut off? Interested in the mechanics behind that. Seems odd that a short connected to an oil px gauge would make the engine run with the key off.

 

[alldodge]

If it was a Merc it would be under the helm, most often an inline fuse on the Red/Purple wire going to the ignition switch. Being a VP its either there or the fuse panel.

Not seeing how it was wired, my guess is the main hot (Red/purple) is mixed up with the Purple.

 

[jg5343]

Ok. Found and replaced. There is a 20A CB on the switch panel, which was not tripped. One of the "pimple" type. I tested the ignition switch and found it to be working properly. Traced all the wiring out locally, and then into the engine compartment. There is a CB and relay panel on the forward starboard side on top of the engine with a black snap in cover. In that was a blown 20 amp fuse labeled accessory panel. I am assuming that it supplied power to the engine protective circuit associated with low oil px/high temps. Blown for obvious reasons above. Thanks for the help, just needed to keep looking for the right fuse panel. Not alway easy in these ever more complicated wiring harnesses.