View Full Version : Ballast fill issues - be sure to check switch wiring

05-22-2013, 03:04 PM
Just wanted to share a recent ballast investigation / resolution to help others in knowing what else to look for ...

On our 2005 MC X-10, the KGB ballast would empty but attempting to fill it would trip the breaker. Upon resetting the breaker, both lights on the switch would illuminate.

The local MC dealer's best guess was that a worn, inflexible impeller was preventing the pump from flipping the vanes when going from empty to fill. It seemed like a plausible explanation (and we've had great luck with the dealer's service department, etc), so we went about replacing the impeller only to find one in mint condition (it's a "new boat" to us, so we weren't sure about the ballast impellers - raw water impeller has already been replaced). Even with the impeller out, the pump would still not turn in the opposite direction.

So we moved our investigation to the 3-position ballast switch. Upon removing the switch, we found the culprit. The insulation on a pair of the more drastically bent wires had cracked, and the exposed stranded copper was creating a short. Fixing the wires put us back in business.

Figured I'd share.