2-Way Switch Problem

[nickldn]

Hi,

I have recently replaced some switches in my house and now seem to have a problem with the 2-way switches on the stairs.

The switches light two lamps at the top of the stairs and it used to be possible to turn the lights on and off with either switch.

Now the lamps can only be turned on and off with either one switch, or the other.

It isn't possible to turn the lights on with the switch downstairs and turn them back off with the switch upstairs (and vice versa).

The switch downstairs has 3 wires blue (Common), red (1 Way) and yellow (2 Way).

The switch upstairs has those same wires going into the same terminals, as well as the wiring to the lamps.

Both switches work independnetly, but not together and I've run out of ideas as to why.

Can anyone help?

Nick

 

[ColJack]

where does the wiring to the lamps go in the switch?

should be L1 and L2, NOT com and L1 as a normal switch..

 

[nickldn]

Wiring to the lamps goes into the Common and L2 terminals.

I've tried changing the wire in the Common terminal to the L1 terminal, but that made the lamps not work at all using the switch upstairs.

 

[ColJack]

I don't believe you...

if the downstairs switch has the same wires as the upstairs switch in the same holes, then putting the wires to the light into L1 and L2 would make it work..

get us photo's of the backs of the switches and the wiring at the lights and we'll see if something untowards is going on..

 

[ericmark]

Hi,

I have recently replaced some switches in my house and now seem to have a problem with the 2-way switches on the stairs.

The switches light two lamps at the top of the stairs and it used to be possible to turn the lights on and off with either switch.

Now the lamps can only be turned on and off with either one switch, or the other.

It isn't possible to turn the lights on with the switch downstairs and turn them back off with the switch upstairs (and vice versa).

The switch downstairs has 3 wires blue (Common), red (1 Way) and yellow (2 Way).

The switch upstairs has those same wires going into the same terminals, as well as the wiring to the lamps.

Both switches work independnetly, but not together and I've run out of ideas as to why.

Can anyone help?

Nick

The circuit you talk about should work if the "wiring to the lamps" connects to L1 and L2.

See

for general wiring diagram.

There are other ways to wire two way switches

The first is school boy method a problem as normally we have feed and return going to one switch the second is better as both feed and return go to same switch.

 

[sparkwright]

are you certain blue was common?

 

[nickldn]

I think the situation is a bit more complicated than I at first described...

There are 3 wires going away from the switch and one wire coming in.

Untitled

• nickldn
• 22 Aug 2009
• 1

The neutral (black) wires on all 3 cables going to the lights seem to have been joined together and taped up. They don't go anywhere.

The live (red) wires from 2 of the cables go into L2, the live (red) wire from the 3rd cable goes into Common.

Untitled

• nickldn
• 22 Aug 2009
• 1

The wires from the switch downstairs go into all three terminals.

Why there are 3 wires to 2 lamps I do not know. It's very hard to decipher this!!

 

[sparkwright]

at the switch you have phptographed take out the blue and red you have in the common terminal. put the single red wire into the common terminal. put the blue and red pair in the remaining terminal.

make sure at the other switch red is common.

 

[ColJack]

ah so you DO own a camera..
now repeat after me..

"next time I mess with electrics, I WILL take digital photo's of the wiring BEFORE I start messing with it.."

now.. that red is quite clearly STILL in with the blue..
take it out and put it in with the single red...

 

[ColJack]

nm

 

[nickldn]

IT WORKS!!

Thank you Sparkwright you are most definately the man!

I changed 12 switches that day....they all went smoothly except that one.

Thank you very much for your help.

Nick