I think I know the answer, but...

In the process of doing another project, I discovered that 14-2 plus ground Romex-type cable had been used with a 20 amp circuit breaker. The circuit fed outlets in a bedroom, including a window air conditioner. It has been this way for at least 20 years. I changed the breaker to 15 amp and decided to use the 14 gauge cable for a general lighting circuit and rewire the outlets with 12 gauge cable connected to 20 amp breaker. When I spliced into the 14 gauge cable, the black wire insulation was fused to the Romex covering - I imagine the wire had overheated and partial melting occurred. The insulation was not brittle, just stuck to the coat.

The question is, do I need to replace the entire 14 gauge cable? This is on the third floor of an old house and it would be difficult. I have looked over a 10-foot length and the cable appears intact from the outside. Any thoughts?

Sounds like overheating, you lucked out this time, catching this like you did.

Shows what an air conditoner can do for damage.

Imagine what the cable can be like hidden in walls where it took longer to cool or dissipate heat.

Any part of the cable can fail, this won't get better on it's own.

Replace the cable, and sleep at night.

Oh well, that's what I thought you would say!

Thanks a lot TK for your always valuable advice.

Dennis