Flashing overspeed

[d11gnccer]

Carrier model: 0053130
Serial: 3007V24542
45KW 2.4L mitsibishi


I was sent to a call 40 miles above our typical service area because the customer could not find anyone to service unit.

Generator will crank but no spark is present and goes into a flashing overspeed lockout. From what I can gather the controller doesn't see the engine cranking. I was on tech support with Generac but found it difficult to stand in the rain, up to knees in mud, with a phone that had minimal service in one hand, and multimeter leads in the other. They was pointing me to flywheel sensor and cam sensor. At that time I didn't even know where they were located and was frustrated.

Any input on what type of readings I should be getting or how to systematically approach the problem. No diagnostic manual could be found under generac website.

[d11gnccer]

Just to add some information as I learn and go in case someone does a search later on.

Original sensor reading was 1.8 volts which I was told is a little high.
The flywheel sensor should give a reading of 1-1.5 volts on pin 9 and 10.
Ohm readings on these sensors are around 1000. After replacing control board and pulling sensor to clean magnet and adjusting to get 1.2 volts output, board still flashes overspeed. Took a look at the cam sensor for after getting an open circuit ohm reading. The end was chopped off and frayed wires protruding from end of sensor. The cam sensor should be set at .015"

We are ordering a cam sensor and will see if this solves the problem.

[Kelly Myers]

This is going to take care of your problem. I've seen it numerous times. Be very careful replacing that sensor!