Garage door opener gremlins...

Have an old Allister ARD 11 door opener that started operating on its own the other night...and this thing is baffling me. It goes up and down whenever it feels like it...sometimes just occasionally, sometimes almost non stop. I worked on it last night after it went into complete meltdown mode (up down up down stop go reverse up down stop go etc etc etc) and it seemed like things totally changed after I tightened the 3 terminal screws where the remote module/door button wiring attaches...they were pretty darn loose before. It acted perfectly after that, even sounded different, but then the door was up again this morning, then back down by the time I got out to the garage.
It has no "eyes", so that's out.
I have the remote control module completely removed, so can't be a remote issue.
The wiring for the door opener buttons is removed from their terminals (at the opener)
I have examined the internal wiring, connections, and contacts pretty darn well, and everything looks fine.
This is an old electro-mechanical model, so no circuit boards to fail...and I would really like to fix it rather than replace it with a modern piece-o-junk model...these things were known to be tough!
I went through the factory troubleshooting chart and they gave 4 possibilities for this problem, most of which I had already eliminated, the rest just plain checked out fine.
Anybody have any other ideas?

 

Here is an internet photo of the top of the unit...mine is pretty much exactly like this one, except the open stop switch and the close stop switch is made into one switch on mine, instead of two separate switches like is shown here...I need to see if I can fine a good electrical schematic for it, but I wonder if this switch/internal contacts failing could cause this problem?

 

one way to test the switch would be to find out if it is No or NC and then simulate it functioning to eliminate or indicate the switch. Course, intermittents can drive ya bonkers.

I have the newer ones and have spent a bit of time setting the adjustment for down to just kiss the floor, stop, so the weight of the door is on the floor with out the gears and chain trying to push it past the floor. ( too much past the floor will result in a fail and it will go back up - why I decided to adjust it better than the installer. ) Unfortunately the pot controller is temperature sensitive. So I finally have a middle of the road setting and ignore it not being quite perfect. I think I'd rather have limit switches,

 

I think I'm going to clean these contacts (on the right) I'm wondering if one of them kinda/sorta welded for a minute if that could cause this issue...of course the stupid thing won't act up for me now...it'll wait until the middle of the night to go berserk!
Think I'm going to replace the motor capacitor too, I heard it hissing a bit after a few trips of up/down...it still looks and smells fine though.

Here is my open/close switch.

 

Switches are NO, and already unhooked at the opener, so that eliminates mouse chewed wiring too.

Remote module is removed, so that completely eliminates that possibility.

 

Agreed...I'm done filling my pie hole now, so Ima go clean that up...

 

Both types here...but mostly the ole Buss fuses still...I go through and check tightness on the fuses at least once per year...and scan the box with an infrared camera to look for coming problems...I did have an auxiliary fuse box/disconnect for the central air that I replaced a few years back...it would just get warm after a while, and nothing was loose, everything appeared to be fine...made me nervous so out she went! I pulled in one size larger wire at the time too, it was borderline big enough and would get just a bit warm after a while...good thing, as the replacement AC unit that came later was a tad larger.
I have started replacing the ole fuses with the new Buss fuse replacement breakers as I pop 15A fuses (user error) since the old fuses are getting stupid priced now!

 

I have one on a commercial opener. Button on the wall up down stop and a remote with a single button. Programmable code with dip switches. Never had any issues with it doing it’s own thing. Installed in 2001 and used daily multiple times. The receiver looks like this

 

Well, I cleaned those contacts up, we'll see what happens...I have my "bear trap" set for the night...it hasn't stayed put the last 2 nights...I was trying to figure out how to tell if it activates during the night, especially since I have the door uncoupled now...no way to tell if it did anything if it ends up back in the down position by morning...so I wrapped some TP around the track/chain...if it moves the TP will be torn up.

Those contacts cleaned up pretty well, but I think I'm going to try and get a new relay assembly for it...the more I think about it, the more I think these contacts lightly welding could cause this issue. I couldn't find a make/model/number on the relay, so no idea if I can find a new one or not ...probably NLA from the OEM if I had to guess...never seen one quite like that before, so I dunno...

I find this old electro-mechanical stuff fascinating...some real engineering went into this stuff...and even though its often very complicated, with lots of moving parts, its often just as, or more reliable then the new full electronic stuff...probably because things were usually build to last in the old days, rather than "built to a price point" like is so common now.
This light switch is interesting...bi-metallic strip with a coil on it...I think after the light is on for a while, the coil heats up and opens the contacts up...at that point then I think the contacts on the other side make and keep the coil energized to hold it open/light off...when you hit the door button it energizes a relay that opens the "holding coil" and allows the light circuit to close again, process starts all over again. I'm not sure, but I wonder if the draw of the light actually helps to heat the strip up...in other words a 100W bulb would turn out faster than a 60W would...and a 15W LED may not turn it off at all? I dunno, just guessing since I don't have an electrical schematic yet.

 

I had the same thing happening at my old place.....garage door opening without any reason. Woke up out of a sleep more than one time to "respond" to the unwanted opening!!!

Couldn't figure it out. Lots of adjustments that went no where to remedy the problem; ended up changing out the powerhead and that helped the most. Except, it was a used powerhead and that gave up the ghost too!

Replaced both door openers within a year or two time frame and never looked back.

I'm thinking thats what you'll be doing also,

 

Maybe...but it will be a long time coming, I don't give up easily when it comes to letting "broken things" best me...got a stubborn streak that runs pretty deep sometimes...

 

You will figure it out Brother! Good luck...

 

Solenoid/relay, yeah...it's that assembly in the first picture of post 6, that's the only relay, otherwise its the motor, a cap, some limit switches, and a 24V transformer...oh, and the "light switch"...that's about all there is to it.

 

I'd start by replacing all of the microswitches. Cheap and easy. Dust infiltration causes them to not fully move inside and even something like temperature swings can cause a false action.
To test a motor cap using 120v.
2650×amps÷actual volts=MFD
A amprobe with needle lock speeds up the test. Energize lock the needle read the volts deenergize.