Kathryn, welcome to the forum!
Could you supply more details?
What model coach?
What model genset? Installed or portable?
Does you WP fuse blow immediately? Does it work for a while after replacement?
Stating the obvious here for some, a fuse blows when excessive current travels thru it.
Having said that, you could have shorted wiring, a bad pump motor, or even debris in the pump impeller causing increased amp draw.
Also ensure the fuse is rated properly for the circuit.(Check your pump for a tag that would show amperage. You could also try disconnecting the pump wires from the coach and via a fuse of the same rating, see if the pump would operate properly with a power and ground hooked directly to the battery for testing. This would narrow down a bad pump or shorted coach wiring.
Regarding your CO alarm……..This is concerning and VERY Dangerous! I would recommend that you STOP USING the genset until you get this figured out……….your safety is at risk!!!
The CO alarm obviously is trying to tell you of the danger within your coach.
CO would have to be entering the coach in some way to set the alarm off.
If a portable set is being used, try a different placement, consider wind direction and ensure the exhaust is being blown away from the coach.
If an installed set, the genset exhaust system will need to be inspected for exhaust leaks. Ensure inspections from the set itself all the way to the end of the exhaust piping. Be sure to check for leaks, smashed pipe, and the proper distance of pipe extension beyond the coach wall.
In either case, be sure to check your slide seals to ensure that they are in good shape and have flipped properly on all sides. Ensure windows and vents are shut and sealing. Check microwave wall vent.
Also , if the exhaust is exiting near the wet bay, one entry point could be where the water hose enters the wet bay.
Does this only happen when the genset is running?
Remember that your oven, furnace and water heater (when on gas) are CO producers as well.
