Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Hello, my name is ***** ***** I am going to assist you with this.
What is the serial number of the genset?
It really does not make any sense that it would only crank 1/2 turn after replacing the controller. That should not have any effect on anything.
The starter is located on the back side of the engine, up high.
You can access it through the top access panel.
The starter is the first place you need to check. It is doubtful that this is something internal, but do not rule it out completely just yet.
You state that you checked K2. Exactly how did you check it? Did you simply pull it out and test to see if it was switching? Or did you actually check to make usre you had good 12V going through it while it was activated?
Yes, the solenoid is built on to the starter, just like they were on older cars.
The starter is on the back side of the engine, directly opposite the oil filter.
If you were to drill a hole through the oil filter, and through the block, it would hit the starter.
Yes, I have the schematic. I have been an Onan tech for 15 years.
Starter disconnect occurs when the controller senses that engine speed has reached 800 rpm. It gets speed sensing from the frequency of the AC output.
From what you are describing, you are down to 1 of 2 issues:
1. Bad connection at P1-6.
2. Bad controller.
In 15 years, I have never seen a pin go bad on its own (it's a different story when people go to probing in there with a multimeter), but I have replaced many controllers.
The power to activate K2 comes directly from the controller.
If you jump 12V to pin 85 of the K2 (pin 30 to 85) this will be the same as the controller powering up K2.
If it still only cranks 1/2 turn, there is a problem somewhere past K2.
If it cranks normally, the problem is before K2.
The only thing before K2 is the controller and the wire between the controller and K2-85.
Since you did replace the controller, it is very possible that you bent/damaged a pin. They are very small, and easily damaged.
Did you find anything yet?
Was this what you wanted to know?