3 way switch replacement problem.
I have two lights connected to two 3 way switches. The one at the bottom of the stairs was old, probably original to the house so I decided to replace it.
Knob and tube wiring, not really color coded but two attached to the right look somewhat red and also seem to come into the box together, left one from a seperate spot. Both old and new had one screw on left and two on right. New was black on the bottom right and brass for the top two. I connected new just as old was and now if the top of stairs is up the bottom switch turns it on/off but if the top of stairs is down the light is always off.
I'm thinking either I didn't transfer the wires correctly or the common is different? Can I just try to switch which one is common? There are only two other options.
I have a multimeter with two probs but I'm not that experienced with electrical. I've read other posts but have just gotten confused, which is why I'm thinking to just rewire until it works.
Thanks for any suggestions!