I need to add a new receptacle to a room. The only convenient source of power for that receptacle in behind a light switch. The challenge is that the aforementioned switch is located on the end run of an existing split receptacle. So there is only 1 cable running into the switch box, coming from existing receptacle, and white wire is marked as hot. The existing receptacle is too far to be a viable solution to wire from there. My only option is from switch box. Am I out of luck?
How do I add a receptacle from a switch located on the end run of an existing split receptacle?
That switch box contains 2 hots and no neutral. So without running any new wire, your only option would be to re-wire the outlet so that it is no longer switched and use the switch box as a junction box.
Here's a before and after diagram. Note that the "neutral" between the switch and the outlet is actually your white wire that has been relabeled hot.
Thinking about it again, you could make your NEW outlet switched in this configuration.
1+1 for another example of how those switches that do nothing are born! I think it's in all building codes that every house must contain at least one switch that controls nothing. Mar 17, 2011 at 20:43
2ha! notice i said use the switch BOX as a junction box. i recommend putting a faceplate over the box. switches that seemingly do nothing drive me NUTS.– longneckMar 17, 2011 at 21:08
agreed, blank faceplate or make the new outlet switched. Note that using 2-conductor wire, the new outlet would be totally switched. If you run 3-conductor (14/3) wire, you'll be able to do a split receptacle - one switched, one constant.– gregmacMar 17, 2011 at 21:54
Oliver, the short answer to your specific question is YES, you are out of luck. The previous discussion is viable, but requires rewiring in the switched outlet to turn the conductors going to the switch back to the normal hot/neutral/ground configuration for use with a receptacle , and will result in no longer having a switch and original switched receptacle. Also note, if you do decide rewire the switched receptacle as a source for another receptacle, you may want to replace the actual receptacle because the bridging tab will have been removed if only one half of said receptacle was switched. Not necessary if both top and bottom are switched together. This is rare however.