4 wires (plus ground) running to 3-way
 

Why would someone run 5 wires (3 black, 1 red and 1 ground) into a 3-way switch?

If 1 of the blacks is the common/hot, then would it make sense to splice the other 2 blacks to one terminal, the red to the other terminal and ground to the ground terminal?

http://www.electrical-online.com/wiringdiagrams.htm


You might find a variation here that uses that wire combination. Perhaps they were also supplying a separate always on circuit for an outlet?

Welcome Kpster:
Or it could be a double pole switch, 2 hots in, 2 hots out and a red common. If it is working don't change anything.
Glenn

Who knows. Maybe there is a feed and also a feed out?




Absolutely not!
There is NO way to tell what is what without testing. If one wire is the common you would definitely NOT have two wires on one of the traveler screws. There is NO reason at all for doing that.
It is perfectly typical to have two (or more) feed wires spliced with a pigtail to the "common" screw.

i replaced a receptacle a few weeks ago that had 7 wires... talk about a pain in the butt..... I understand your frustration.. although not the number of wires.... but... my outlet is still working well....

one wire would be the line the second one the neutral the third and fourth would be the travelers between the two 3 ways and the fifth would be the return from the far switch hope this helps

Perhaps there are two switched legs coming out of the common. You don't mention how many (if any) neutrals are in that box. I don't know why someone would have the 2 switched legs, but without seeing the installation it's hard to tell............

what the @uc% ?
 

It is impossible to guess, without knowing what the heck is in the box, like what color and whats tied together. You either have a three way with a pwr. tap or a three way with a double switch leg....very common if lights are seperated by intense framing and long distance, or your at a 4way switch with 4 screws and a grnd. screw?????. at any rate hope this is informing, or re-post with more info and exact nature of problem, and maybe we could be more helpful.

I have a 3-way switch with 4 wires(2 black, 1 red, 1 white). I know which is hot. The other black wire has been marked white. The 3 way switch is in a circuit that controls my lights and the living room outlets are on the same circuit. I know the hot wire is my common, but what would be the logical answer for which two wires are put on the same screw? The red and white wires come from the same bundle. The two black wires come from 2 other separate wires...