The yellow arrow points out where on the tank monitor numbers should be that tell us how full our tanks are. The only one that really, really matters is the black tank (toilet waste) which we keep closed until this gauge says it is getting near full and needs to be dumped. My wife says she can tell by a change in sound when she flushes that it is getting time to dump. She has better hearing than I do, which isn’t saying much given how bad she has always said my hearing is.

The back side gives credence to the saying – An RV is a bunch of wiring surrounded by a box. The display was burned out and a replacement monitor is on order.