basicequipment
Active Member
I've got a Takeuchi TB180FR excavator that has an issue with the auxiliary control system. None of the functions work on the lefthand control. The previous owner had already had the dealer try to find the issue with no luck. The dealer changed out the switches in the joystick. I have looked over the schematic and checked continuity of each wire from the joystick to the controller, then from the controller to the solenoid valves. All of the wiring is good. I ran a 12v jumper from the battery to the solenoid valves and the functions worked. The only other potential problem I could see was the propotional controlller. It has 12v coming in and the ground is good. Since I did not know how to test the controller, we replaced the proportional controller today ($850) and that did not fix the problem. I decided to go with what I understand and I removed the controller and made jumpers connecting the appropriate power, ground and signal wires at the controller plugs in place of the controller. This put the auxiliary circuit back to work using the push buttons (running a thumb) but of course the proportional feature does not work. My question is; does anyone have an idea about what I may have overlooked in my attempt to identify the problem with the factory control system. There were a couple other unidentified wires in the harness and my only assumption is that they could be sending a signal to the proportional controller, (safety switches???) telling the controller not to send signal to the solenoid valves. The schematic supplied by the dealer is somewhat incomplete and does not match up with the factory wiring and pin locations. Any thoughts would be greatly appreciated.