Originally Posted by Meben
I have a new 2020 brookstone 344fl. Tank level gauges did not work from dealer. I know they won't last and aren't reliable but would like to have them working while its new. Rather not go back to dealer and wait forever if I can help it. I check wires on monitor panel and all look connected. My question is how difficult is it to get into the under cover to check wires on tanks and what would be the best way to resell it after I open it. Really only concerned about fresh water tank level when camping without city water.
Easiest way is to cut a window in the plastic. Make two cuts running fore and aft and on at the rear of these two cuts so you can hinge the plastic down, hinge at front. Make it big enough so you can reach in and access the end of the holding tanks close to the discharge pipes.
To re-seal, two options. One is some wood lath attached to the inside of the plastic along the edges. Overlap the cut line and fasten with short sheet metal/wood screws. Close up panel and secure it to the lath with screws. Then tape over with some Gorilla Tape (after wiping plastic clean with alcohol or acetone for good stick.
Other is to just tape although I have found that sometimes just tape comes loose. Another tape for sealing that works well is the adhesive backed aluminum tape used to seal heating ducts.
Before cutting holes I'd make sure the tank gauge panel is receiving 12 volt power first. If no power, no point in cutting open the belly cover until you've eliminated that problem.
As for these gauges not showing correct readings, might consider replacing sensors in the tank with the Valterra "Horst Miracle Probes"
They're designed to prevent false readings that occur when multiple probes are shorted either by toilet paper or crud buildup on the tank wall.
I replaced mine in March and so far so good.