T190K TRK-Gold Pkg Serial 531615006 I have a 2006 Bobcat T190 with the left thumb switch on the right steering level not working. It’s been a couple of years since I used it but it worked then. Moving the thumb switch to the right works with no issues. Moving thumb switch to the left and nothing happens. I have one long beep at startup indicating the Active Alerts are working. But if I disconnect ether coil from the solenoids I do not get three beeps or a Active Warning. Both coils measure 4.5 ohms and I see not broke wires or lose connectors. Putting a metal rod in coil and activating the thumb switch to the right I get a magnetic field but putting metal rod in the other coil and pushing the thumb switch to the left I do not get a magnetic field. Took solenoid apart it appears to work correctly with no signs of rust or fluid build up. So I think that leaves me with a broke wire and/or a bad thumb switch (which is encased in epoxy so can’t take apart) and/or a bad PWM module if this unit has one. So my questions are: does someone have a wiring diagram showing the wire colors and wiring of the connection under the cab so I can check the thumb switch? Also if this unit does have the PWM module (different post have different answers) I do have a oscilloscope if someone has a image of the PWM waveform. From what I read online it should be 9Vp-p which a changing duty cycle. Thank you for any help or guidance.
Sorry don't have the wiring details readily available available. However my experience would lead me to suspect the thumb switch has failed.
Thank you for the reply. I'm hoping that it's the switch or a broke wire. Thought about it more and I'll ohm all the wires on the connector while working each control. I think if it's the switch one wire would show open. Not sure if all the controls are connected to ground or if they have a floating ground.
The wiring connector for the right hand thumb switch is under the cab where wires from thumb switch controller connect to wiring harness: Connector C409 B white goes to one end of the potentiometer (4300 hydraulic wire number) Connector C409 B white/red goes to wiper of the potentiometer (4320 hydraulic wire number) Connector C409 B white/black goes to the other end of the potentiometer (4310 hydraulic wire number) Using ohm meter the wire going to the switch and the switch itself can be checked in both left and right directions. Hopefully this helps someone else
Thanks for sharing your extensive testing and knowledge to help others, did you solve your issue? I too find that it’s often the switch itself, the rocker appears to wear out and with certain pressure/angle, sometimes I can get them to work, but eventually just replace. Not a cheap part, the entire handle is pricey from bobcat, about half price aftermarket. Good luck
Ohm meter give these valves for thumb switch: Total resistance is 4.9K Detent resistance is 3K Left resistance is 1.5K right resistance is 4.2K Thumb switch was good, so tracking wires back to the PWM source next. Hard to understand the wiring diagram in service manual so have to do research to understand their notations and numbering system. The manual does not have a block diagram or an explanation of how system works. Learning the hard way, LOL.
Below is the PWM signal going to the solenoid that is working using an oscilloscope