TIL a weird trick for a sticky door operator on a 90s Dover

Got a call for a car door that wouldn't close right on a 1996 Dover hydraulic. Spent three hours checking rollers, guides, and the clutch. Turns out the issue was a tiny bit of old grease that had hardened inside the door operator's limit switch, making it think the door was open when it was shut. Cleaned it out with some electrical contact cleaner and it worked perfectly. Has anyone else had a phantom door problem that turned out to be something simple like that?

4 comments

4 Comments

adamt841mo ago

Ever think maybe both things can be true at once? On those old hydraulics, a sticky limit switch is a super common fix that lasts. But Elliot's right, if the clutch is already worn, fixing the switch just buys time before the real failure. I've seen it go both ways, honestly.

erickelly16d ago

You see that "both things can be true" pattern everywhere, like a quick fix that hides a bigger problem.

elliot_mason621mo ago

Actually, on those old Dover operators, it's usually the clutch adjustment that gets you. The limit switch is part of the circuit, but the clutch slipping a fraction can cause the exact same phantom door signal. I've seen it a dozen times where cleaning the switch helps for a week, then the real clutch problem comes back.

mark_green1mo ago

That clutch point from @elliot_mason62 reminds me of a time I chased a phantom door on an old Montgomery for hours.