My excavator was running perfectly fine and then just killed. I cranked up ran for few more hours then happened again and will not crank.I lost all power to my dash and everything. I started with fuses and the battery fuse was blown. So I changed it and it works. I am getting fire threw my starter relay and battery relay by batteries. There is one more relay I don’t not know what it is for. I have no power at that relay. The machine will crank instantly then kill. The electric kill switch does not stay in once the machine is cranked. I have tied the kill switch so the machine runs and oil pressure and temp gauges works properly. My question is could it be the relay I do not what it is for or the electric kill switch. Also tested alternator and it is charging properly.
Do you know if the engine has a single valve cover on top or multiple valve covers. The engine with the single is a Komatsu engine and the multiple valve covers is a Cummins clone. The shutdown systems are different between the engines.
It is the Cummins clone engine.
As I recall those have a solenoid coil that shuts down the engine. The usual issue is the shutdown coil itself being shorted through. That could have caused your burned fuse. As I recall, there is a diode somewhere in that system that also blows through and allows current to back feed to somewhere else. I don't have a book for the machines with the Cummins clone so hopefully someone here can provide a schematic.
Leger, would this be of any help to you https://www.plantkeyshop.co.uk/epages/es132531.sf/en_GB/?ObjectID=71364828