# Selector switch



## chicken steve (Mar 22, 2011)

work the switch and meter each position......~CS~


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## Chris Kennedy (Nov 19, 2007)

chicken steve said:


> work the switch and meter each position......~CS~


Agreed, and in addition there is probably little schematic on the contactor block/s that will help.


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## darren79 (Dec 20, 2011)

So I figured out the switches but am now having trouble to get it to work properly.

On the switch there is two contactor blocks, one for open and one for close. I can get it all to work except when you turn it to open, the door will go up and not stop when the switch moved back to the centre. Close works as it should.

From the liftmaster door opener I have a common, stop, open, and close.

I tried running the common to both sides of the contact and then the open and close to the other side but with no luck.

Anyone have any ideas on how I can get this to work.


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## D-Bo (Apr 15, 2012)

darren79 said:


> So I figured out the switches but am now having trouble to get it to work properly.
> 
> On the switch there is two contactor blocks, one for open and one for close. I can get it all to work except when you turn it to open, the door will go up and not stop when the switch moved back to the centre. Close works as it should.
> 
> ...


Could be something in the door opener. Anymore all the newer commercial overhead doors have a digital board where you can adjust the travel and limits. Seems every new door I do the installer has to come back and tweak something after power is applied because I sure as chit am not doing it. Just pass the buck


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## etb (Sep 8, 2010)

D-Bo said:


> Could be something in the door opener. Anymore all the newer commercial overhead doors have a digital board where you can adjust the travel and limits.


True on better brands, but not crappy ole liftmaster.

To OP: it sounds like you're trying to solve the problem but from my perspective it sounds like you haven't looked for the schematic (inside the opener cover or in the manual or on the internet) and have also not used your ohmmeter to test the existing switches to see what you need.

The liftmasters I've done all use 4wire controls. As you mentioned, COM, UP, DN, STOP. COM really is a common wire. Touch it to UP and the door goes up; to DN the door goes down; these are NO circuits. COM must always be wired to STOP for the door to operate; break that connection to stop the door.

If I read you right, you have a three-position switch and you say you have two contact blocks. From your description, I visualize this, except momentary:








Turn left and the left contacts close, turn right and the right contacts close.

Normally, you want the door to keep going up or down after you release that switch. If so, take your COM to each side of the switch, and UP to one side and DN to the other, like you said you did. Stop button would be a NC pushbutton that is separate from up/down; wire it between STOP and COM.

But it sounds to me like you want the door to STOP when you let off the switch. In that case, you need stack-on blocks; the differ for each manufacturer, but look something like this:








Wire COM from opener to COM of all blocks. On up side: wire UP from opener to NO of first block; wire STOP to NO of second block. On down side: wire DN from opener to NO of first block; wire STOP to NO of second block. So when you hit left, COM-UP is completed and COM-STOP is completed, etc.

But really, you need to ohm-out the switches you have. And it is still best to look at the schematic to check what it wants. If no schema, lookup model # on google.


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## darren79 (Dec 20, 2011)

So up and down from the controller go to the same point.


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