I recently acquired a Kobelco Sk200LC Mark 4 excavator with the Cummins 6BT engine. The previous owner had rigged a PTO push/pull cable to the fuel shutoff. I bought a new 24V fuel shutoff solenoid and installed it. Machine fired right up but would not shut off with the key. Solenoid got super hot. (Probably why it was rigged up with a cable) I did some trouble shooting and it has me stumped. There are 3 wires that plug into the solenoid. A black ground, a white PULL wire and a White with Blue stripe HOLD wire. With the machine off, the key on and the solenoid unplugged and testing with a multimeter the Pull wire shows 24 V momentarily then goes to 0 (as it should). The hold wire shows 24V until the key is turned off and then goes to 0 (as it should). Here lies the problem, when the machine is running the Pull wire reads 28V constantly(regardless of key position) What could be the cause of this? Where is the relay for this circuit located? I have the service manual and wiring diagrams but they haven’t been a whole lot of help. Any assistance is greatly appreciated.
I can’t help with the relay location but I can tell you, if the plunger isn’t bottomed in its housing, you’ll get all sorts of things going wonky. Remove the plunger from the shut off LEVER.. Operate the s/o by hand and mark its location.. use a pen or marker on the governor housing.. Now put the solenoid back up but don’t hook it to the lever…and operate it..BY HAND..bottoming the plunger.. Is the plunger bottomed when the lever is at the marker location.?? If not, there are adjusting nuts on the rod.. Hope that helps a little..
Just to follow up on this thread in case anyone runs into the same issue. I finally found the relay for the fuel stop solenoid. It is located behind the seat buried in the 3rd level of electronics located above the heater. In my case the relay contacts were corroded closed and causing the “Pull” wire of the solenoid to constantly be energized while the engine was running. I replaced the relay and that solved the problem. I will also mention there is a 30amp fuse in the wiring harness behind the seat that is also part of the fuel solenoid circuit. (Mine was blown).