Odor in bathroom of 1971 Overlander

[maxcor]

We have a terrible odor coming from somewhere in the bathroom of our 1971 Overlander. It is only recent, and it has not been used all winter. Any ideas?
Maxcor

[Sundance]

I'm running on only my reading here and have no experience
with an RV issue, but..........

Check and clear the vent stack. Chances are it is plugged
with debris.

I am considering on of the swiveling, vane style caps on
mine. It is supposed to aid in the air movement.

Sewer gas is not only bad smelling, it is dangerous.

Good luck

[InsideOut]

Either that or a new leak in the black tank...

Hope it's the stack ~

Shari