Now I have a limit switch issue on Y.....

Per my other post, I have been trying to get connected to a rotary on a late 90s VMC. I got the rotary going ""finally"" but now unable to home Y. This has NEVER been an issue before so rather concerned. Does anyone know how to find the bit to see if the control is seeing the switch? I also would like to directly test the switch with a meter but not sure where to find the plug for it. There is an Amphenol connector on the side of the cabinet that indicates "limit switches" but I am not sure if the Y is in there or not.... I just need to trouble shoot and see where it plugs in so I can learn if this is a switch issue or a control issue.


Right now, it will move like it is trying to home, then error with alarm 104 and I believe it is hitting to bump stops on Y. I plan to call Haas but really need to get this going and not wanting to wait for them to open...

Para/diagnostics button, hit it twice. You should be on "Discrete Inputs2" screen. About halfway down on the left is your "Y Home" limit.

It will only go to limit switch during homing, and normally at bit stays at 0. Will flicker to 1 when setting.


My limit switches always go...or went. Tech taught me a quick trick to making them last longer...load the working part of the switch up with grease to keep the coolant out.

I also keep and extra switch or two on hand and wire them in as needed.

Well.....It looks like the Z axis switch is screwed. Never saw an error. Was doing some wire swapping at the terminal block behind the lube pump so I could trouble shoot switches. Y was fine, Z initially looked fine, now it is hosed. I really do not get it but I have it all jumpered right now and the machine is now seeing inputs on all three axis.

I cut all the wire off the Z switch and the switch is surely toast. supposed to be NC, I test it as open but if I slam it down on the bench, it closes. Good enough for me. I will get a Z switch and hopefully get going.

NOTE TO SELF AND OTHERS. If the Z axis switch goes tits up, do NOT take the whole machine apart to run the wiring where it was. Just cut the old wires and run new in a "smarter" path. The way they routed that is friggin ridiculous. I got half way torn down and decided I was going no further. I will come up and out and go down through the main column which drops me right on my termination point. Someone was not thinking on that one....

Try an SL-10 Turret Cylinder Proximity Switch...I asked the procedure, went out to the machine started taking panels off then said the hell with it and just snipped the two wire cord then soldered in the new one...several hours to just minutes.