That week on the 14th floor where everything clicked

Had a rough Monday on a controller retrofit in a 20 year old Otis at a hotel downtown. Got the new software loaded and the car kept hunting for level. Turned out the encoder wires were nicked from an old chain oil leak. Cleaned them up and heat shrunk everything Tuesday. Ran 50 cycles with a full cart and it leveled dead on every time. Anyone else run into encoder gremlins from old leaks?

2 comments

2 Comments

robert_rodriguez661mo ago

That encoder wire issue is a classic Otis problem. I had a 1998 model at a medical office building where the oil had wicked all the way up the cable jacket and into the connector pins. Ended up replacing the whole harness because the corrosion had gotten into the terminal block too. For cleanup I used electrical contact cleaner with a stiff bristle brush, then let it air dry for 15 minutes before heat shrinking. Those old leaks always seem to find the worst spot to hit. Did you check the motor junction box too, sometimes the oil pools in there and rots the seals out.

joseph_murray81mo ago

Seen this exact thing on an old Otis back in 2019. The encoder jacket was all sticky from some long-term oil seepage, and the signal was dropping out on every fourth or fifth run. Had to cut back a solid six inches of bad cable and re-pin it. Also put a small drip tray under the motor to catch future leaks, saved me a callback six months later. What did you use to clean the connectors before the heat shrink?