No 12 volt

[Yachts]

My aquahot display, my awnings all my lights and even the start for the genset are dead.. It's like all my 12 volt has vanished.. Any ideas?? My 12 volt kill button never Stopped my gen start and aquahot display

[77newell]

Yachts: I would first check voltage at the house batteries. If one goes to battery heaven the rest of them go to hell real quick. If the Aquahot display and gen start truely do bypass the isolation switch and those are dead too as you describe then the most likely candidate is the batteries.

[Yachts]

Weird , I merged the batteries turned the ignition key to the on position and the gen would start and I got my 12 volt back.. My battery monitor system shows I have good batteries.. But when I turn the genset off I lose 12 volt.. Is there a switch or fuse that tells it to draw from the batteries and not the generator?

[folivier]

You should have a large fuse connected to your batteries, check that you are getting voltage on either side of the fuse.
When you merged your batteries you were getting 12v from your start batteries.

[prairieschooner]

Sounds like you may have a poor connection at the Batteries. I would most likely start with a Volt Meter and check the voltage before I would start any work but that is me otherwise I would;
Turn off any Charging Source for a while to ensure that they are not Gassing (flooded lead acid batteries produce hydrogen gas when charging) as a precaution pro to doing any work so that I would not create a spark and have other problems. I would then start checking Connections for the Cables at the Batteries, where they connect to the Ground and then the Battery Switch and any Circuit Protection (Fuse or Circuit Breaker) if applicable.

[Yachts]

Is the fuse normally in the battery compartment? Mine is a small slide out tray on the curb side in front of the chassis batteries

[77newell]

One explanation for why you have 12 volts with the gen running is that then the converter would be running and producing 12 volts. If you have 12 volts at the batteries then the suggestion of looking for a large fuse in the system makes sense. I have no idea if such a fuse exists on your coach, my 77 didn't and could burn the house down with some shorts.