I have an O-36 Fastrack Remote switch that has been working flawlessly, then all of a sudden it failed to switch to green. Would stay on red. I physically turned the lantern to green and it would work for a few more switches then stop working. I tried a different remote switch - same result. I changed wiring and same result. Ideas?
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The limit switch cam wears out on these. I have seen successful home repairs here on the forum by folks who have built up the material to bring it back into spec.
As Rob stated. Remove the bottom plate and check the operation of the limit switch.
These are small black switches that get closed by the turnout mechanism at each end of full travel.
With the plate off manually move the turnout via turning the lantern. At the end of travel you should hear the click of the switch as it closes.
If not. Add something to the edge of the mechanism so the limit switch closes at full travel. In my case, I used a piece of electrical tape. It's worked fine for years
Another tip. If the turnout is jamming in one direction. Check the motormount of the small can motor that turns the mechanism.
Mine was jamming at the end of travel. It turned out the motor mount was not fully snugged down which allowed the motor to tilt and gear climb up out of the rack mechanism jamming it.
Sounds complicated, but really it's not and will make sense once you remove the bottom cover.
Another possibility, one that I've experienced, is a bad solder connection between one of the wires and limit switch terminal. It worked for a while probably because the heat shrink tubing was holding the wire against the terminal. Same symptoms as yours, sometimes it would throw from one direction only. Tracked down the issue by checking for electrical continuity between the limit switch terminals and the contacts at the PCB until I found which connection was faulty. Gave the wire a gentle pull and it was not connected.
In the picture below, the soldered connections to the limit switch terminals have Red arrows pointing to them.
Like @RickO I've also seen binding due to loose motor bracket retaining screws.
Sometimes gear binding can also be caused by a shim (small clear plastic about the size of the motor, and usually located beneath the motor) that should have either been omitted/or added for proper gear mesh.
It's also a good idea while you have it open to check that the rack gear screw and swivel rail retaining screws are tight.
Thank you Gentlemen for your responses. I did open it up and saw that the right limit switch? was not closing all the way, so I did as RickO suggested and added some electrical tape to make the connection tighter and it is working as it should now.
Thanks again for your information and advice on this problem!
Mr. Bill
Had the gear jam in ‘Through’ position on one of my O72 switches today. Haven’t used this switch more than ten times. I observed the ‘Through’ position switch triggered just barely before the stop, while the opposite direction switch triggered as much as 1/16” earlier.
I didn’t find this thread until after I fixed it my way - which was to give ~0.030” relief to the hard stop in the ‘Through’ direction, since in my case the rack was jammed against the stop. If it happens again I’ll verify the motor mount is tight per @RickO suggestion above and the other ideas by @ADCX Rob and @SteveH
Rack jam:
Plenty of clearance when triggering this direction:
Barely any clearance between rack and hard stop when limit switch triggers in ‘Through’ direction:
I gouged out about 0.030” to allow more play at end of travel: (but could have added tape to trigger earlier, if I had found this thread before putting everything back together)
This forum is terrific.
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