Sounds like an unbalance in the interior wiring. Hopefully it's twisted pair and not quad. If it's quad you'll need to replace it.
Quad is not twisted pair. The other thing that you can look for is bridged taps on that pair (or try another pair or cable).
If it appears to be related to rain, you should replace the cable, really.
Unbalance happens when both conductors aren't the same length electrically (which is usually the same as physically).
Last edited by Joe Talbot; 12/11/19 06:10 PM.
