2001 merc EFI fuse

[micville1994]

I have a champion 190SX with a 2001 EFI 200HP, the RPM gauge doesn't work but the battery charges.
I check some stuff out and found a blown fuse (lower Voltage regulator) changed the fuse, but it blew again. I didn't even start the boat and the fuse blew.
Any ideas what it could be? I'm thinking bad voltage regular. Everything works apart from the RPM gauge. I'm I able to just switch the RPM signal cable to the other volatge regulator?

Thanks

[Tx Champ]

Short answer is yes. It's the gray wire. Long answer is you need to reace that shorted voltage regulator.

[RickCamilleri]

Tach runs off rectifier, and rectifier also regulates charge on the battery. Replace them both if defective. There's a way to test them, but it's almost guaranteed they're bad