I had the same problem, ended up being a voltage issue. 1 of my 3 batteries went bad, replaced it and it was good to go!

Curious how you acquired the replacement bilge pump? Will Malibu just mail a replacement pump? I’m dealing with a similar issue with the forward bilge pump tripping the circuit breaker. Tommy’s is also my dealer and doesn’t have any service availability. Pretty easy to access the forward bilge. 

If you don't want to buy a 2nd boat, and like this one for everything else, consider having your bride join a private lake.  Can ski there for many years for the price of a new boat, and make new friends that share her slalom passion. 

You should expect to pay between $10,000 to $12,000 in parts and labor for the installation, depending on whether or not you already have high performance AGM batteries and an onboard battery charger in the boat.

I have a 2004 Response LXI Monsoon 340 that I have had an ongoing issue with the  ignition relay's on the wiring harness cluster being popped. The boat will run great but the relay's and harness tends to get a bit warmer than I feel they should.  When I turn the engine off if I don't crack the engine cover and make sure to let the heat dissipate from the engine compartment the next time I try to fire to boat up it will either not start or start then shut of at which time it will not fire again. If I switch the relays around the boat will fire back up but if I was just running the boat this  can take some time or needs to cool down.  I also try and make sure when i am just casually putting around the lake  I have the engine cover cracked or at least blower on.  Any one a similar experience or thoughts or and what could be causing this.  I now carry a couple extra relays in the boat with me. 

Thanks Ed