thumb switch on RH joystick cat 304C CR

[jbernielh]

so yesterday I shatter the back window.. today the thumb is intermittent.. in playing around with it the switch seems to possibly the issue.. a quick look in the parts book it appears that the thumb rocker switch on the RH joystick is part of the joystick and not a separate part..

hard to believe I need to replace the joystick to replace the thumb switch..

don't remember the full serial number but starts with FPK and is in the 2K range

 

[Nige]

in playing around with it the switch seems to possibly the issue.. a quick look in the parts book it appears that the thumb rocker switch on the RH joystick is part of the joystick and not a separate part..

hard to believe I need to replace the joystick to replace the thumb switch..

Sorry to tell you but you do. The switch is not available separately.

Before you condemn it competely you can test the PWM output of the switch provided that you have a multimeter capable of measuring duty cycle.

 

[jbernielh]

thx again Nige.. always appreciated..

negative on the meter.. I haven't looked at the connector plug but I wonder if I can disconnect the plug and then wire in a light bulb and battery and see if it makes and breaks or is it more complex than that?

I guess it would have to be as the speed that the thumb moves seem to be proportional to the amount the switch is deflected.. ease it just off neutral and the thumb moves slow, full deflection and the thumb moves fast..

 

[Nige]

negative on the meter.. I haven't looked at the connector plug but I wonder if I can disconnect the plug and then wire in a light bulb and battery and see if it makes and breaks or is it more complex than that?

Not as easy as that unfortunately. The signal from that switch is PWM (Pulse width modulated). The output is kind of like a square waveform (the Pulse) with a pretty much constant voltage and the width of the waveform is what changes. The signal is measured in "duty cycle" where 0% is one extreme and 100% is the other. Without having actually measured a switch like yours I would imagine the centre position will be 50% duty cycle, around 10% rolled fully one way and around 90% when rolled fully the other way.

Oh, and you can't do anything with the plug disconnected. The ECM supplies what's known as a "pull-up voltage" of about 5v on the signal wire coming from the switch so that Diagnostic Codes associated with the signal can be determined. All measuring has to be done by back-probing connector pins while everything is connected.

See this illustration. The Y-axis shows voltage, the X-axis is time.

 

[jbernielh]

once I realized it was proportional I knew I was out of luck..

as far as the connector plug goes I will check and make sure there’s no corrosion etc after that I’ll probably just wait until it fails completely rather than just shot gunning expensive parts at it..

I’m normally using it at full deflection of the switch open/close.. what leads me to think it’s the switch is that when it fails and I put the switch in neutral and then just move it ever so slightly either direction off neutral it seems to function

 

[Nige]

as far as the connector plug goes I will check and make sure there’s no corrosion etc

A good plan. Always possible to have green crusties in a connector.

When a new handle costs somewhere around $600 I think you might be well adivsed to get hold of a suitable multimeter from somewhere and test the operation of the switch you have now. The % duty cycle should change smoothly between the centre value, minimum, and maximum as you move the switch from the centre position.

 

[uffex]

Good day
If you check the PWM valve output (Pressure) you can eliminate hydraulic pilot issue.
Kind regards
Uffex

 

[jbernielh]

thx uffex I'll keep that in mind..

Nige if you wouldn't mind please.. a little help in finding the part number for the joystick.. I've been all through my parts book and it seems like all the sticks with switches are in the 5K plus serial number range..
mine is FPK 02319

the right stick has the thumb rocker mounted vertically on the back side and a small horn button on the front.. nothing else.. the left stick has exactly the same rocker mounted horizontally for the articulating boom and nothing else on the front.. or at least the outer appearances of the boom switch are the same as the thumb..

it looks like there's a lot of different cat sticks you can change just the handle with the switches but doesn't seem to be the case with the mini's.. oh well

the parts guys at finning couldn't come up with a part number by serial # but indicated they're normally around 1300 cdn dollars... needless to say it's going to have to quit completely before I do anything in the way of buying parts..

put 2 hours on the machine today and it never failed once..

 

[Nige]

Tracing it through from the original build data of your particuar Serial Number you have a 280-2956 Control Arrangement which contains a 283-6508 Pilot Control Gp.
The PC Gp breaks down into 283-6510 LH & 283-6509 RH joysticks.
The handles for those joystick Part Numbers are 283-6512 LH and 283-6511 RH.

There is another alternative but I don't think it's the one you have. Take a look at the illustrations below of the LH & RH joysticks respectively. I'm willing to bet yours don't look like this.?

 

[jbernielh]

thx Nige

I saw those switch arrangements in the IPC as well.. they would look like mine if you took away the round buttons and positioned the rockers down about 1/2 inch on the left and about an equal amount to the right on the right stick..

 

[Nige]

That’s why I posted the illustrations asking the question for confirmation, because I didn’t think they were yours.

What you have for handles are the numbers I posted above - HOWEVER those numbers break down even further.........

283-6512 (LH) breaks down to a 266-3216 Handle
283-6511 (RH) breaks down to a 266-3217 Handle. There is a note against this Part Number stating it contains the "modulation switch", although the switch is not available as a separate part.