DIY: Water Pump Troubleshooting and Repair Tech Support M October 06, 2017 18:33 Follow DJ Wolinsky Published on Apr 5, 2014 The water pump for my Sink/Shower in the van isn't working. I'm going to figure out why, fix it and take you along on the journey. Is it the motor? Is it the impeller? Is it the pressure switch? Let's find out!