I had (have) the exact same issue with my 2018 Compass 24TF. My pump is somewhere under the shower (I think) but I just went into the back of the coach and dropped down on my heels real hard and it would kick on. Sometimes it's good for a while other times not. And of course when I had it in for other issues (AND THERE ARE MANY) it would work every single time, for a week it never failed to come on, not once!... so dealer says Problem Solved.. Good luck.
Steve
__________________
|