[Crackofdawn]

on my 3600 Open the pump is in the engine compartment on the aft bulkhead. I have a breaker on the electrical panel labeled "head" when switched on will start the pump to create a vacuum. I can tell that the pump is running by looking at the DC amp meter on the main electrical panel. Once a vacuum is achieved, the pump shuts off. If you have a DC amp meter on your panel, look at it and you should see it bouncing up and down a couple of amps as the pump is running, if it is holding steady after you flush, the pump is probably not running. Good Luck