On my 79 Excella 500 there is a short plug to right and slightly to the rear of the bottom mounted spare tire. Inside, it goes to an old style phone junction box just to right of the fuse panel and behind the sliding doors. Outlets were in the credenza and beside the TV/12 VDC panel between the rear twins.
I unelaborately run both my phone wire and cable out through the fridge access door. I've been meaning to get fancier about that, but it's a contest to see what I can fix and what it can break, so so far I'm still repairing instead of upgrading.
1975 Argosy 28 "Argosy"
1979 Excella 500 31 "Betsy"
1992 Lincoln Mk 7 LSC
2003 Dodge 2500 Cummins "TowHog"
"Lucy Loosehair" the cat - Airstream mascot
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