Replacing dimmer switch - please help - I have photos!

[jmwalthamstow]

Hi all,

Just moved into a new house and the hallway dimmer switch has gone. It's for a number of halogen lights and is connected to a normal light switch at the bottom of the stairs. I've bought a replacement 1 Gang Dimmer (2 way) and am now trying to wire it but am really struggling as I stupidly took the wires out of the old switch!.

There are 5 different wires coming from 2 separate cables: (blue, yellow, red) and (red & blue). Where should they be placed in terms of L1, L2 and C? From the old switch it looks like yellow was in C, red (not sure which) was in L2 and there were 2 cables in L1.

Photo here:

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• jmwalthamstow
• 29 Aug 2013
• 1

Thanks for any help you can give me.

James

 

[ban-all-sheds]

You need to look at the diagrams here: //www.diynot.com/wiki/electrics:two-way-lighting and compare them with what you have at the other switch to see which of the R/B/Y cores should go where.

 

[jmwalthamstow]

Thanks - that's a great help. From what I can work I think it might be this one?

Untitled

• jmwalthamstow
• 29 Aug 2013
• 1

 

[riveralt]

Okay - so I think you are saying that you have two hallway light switches that each operate the same set of halogen lights in that hallway?
You intend to replace the broken dimmer with a one gang 2 way dimmer.

The wiki picture you reprinted is the way forward - HOWEVER.. you need to check and record the way the three core cable (red,blue,yellow) is terminated in the other switch - i.e. red = C blue = L1 etc.
Because you must replicate that in the new dimmer switch.
For the other cable red and black - the normal process for a switch with terminals C,L1 and L2 would be to put the red into L1 and black(red sleeve) into L2. Then replicate the three core as discussed above.

As dimmers tend to cost more than normal switches it might also be worth implementing this change using a normal single gang 2 way rocker switch and getting it right since they tend to be cheaper than another new dimmer switch.

 

[jmwalthamstow]

Thanks for all the advice. I used the diagram and the dimmer switch is working again. God knows how much money you've just saved me! Thanks again.

 

[securespark]

The dimmer may be working but just check the two switches work together as they should.

This will tell you all the wires are connected between the switches as they should be.