Good morning, I got a 420E that recently lost functions to the stick extension and thumb. I’ve checked all the fuses so far and nothing is blown. Any help would be appreciated
Help might be forthcoming if you provide a machine Serial Number.
Just added
Check your message inbox for an electrical schematic.
Very common problem. If you have the joystick style with the little roller button. If you have cat et, you can go look at the live data. Should be able to see it move from center (0) to full forward (100 I think) and then full back (-100) I think. If it’s faulted it will say data invalid or just stay at 0. Also it usually make the red exclamation light come on. I’ve seen some people take them apart and fix. I haven’t replaced one for an E model for a very long time, but the F models run close to a grand per joystick.
You have the electrical schematic so can also look at the output of the roller switch by backprobing the appropriate wires using a multimeter that has the capability to measure duty cycle. IIRC it should measure 50% duty cycle in the centre, close to 0% rolled vully one way, and close to 100% rolled fully the other way.
So it looks like there isn’t any power to the orange wire RT-25, none of the fuses are blown so I say I’ll have to trace the wire for a break somewhere
Do you mean X800-RT25.? Are you missing power in both handles or just one.? Follow the wires back ain the schematic and you will find a splice where X800-RT25 and X800-RT45 both morph into X800-RT1 which goes to CONN 3 then becomes X800-X800-PL35. Eventually it comes from Pin 44 of Connector J1 on the machine ECM. It is an 8v suppply so you should measure 8+/-0.5v DC between that wire and J764 BR which is the ground wire back to the ECM. Don't measure power between X800 and machine frame ground. It could potentially give you spurious results.