Sewer smell in cabin while driving

our commode seal ,the gate that opens and closes, was not sealing tight ,thats where our smell came from.

If the bathroom sink is hooked to the black tank tube or tank and the water in the P trap is vacuumed out or lost you will have a stink, we run the three fans in to create a positive pressure in the vehicle when we run with the windows open.

Now we travel with one cat so we can not open them too far, some times the cat likes to lounge on the dash board and would probably try to jump out the window, so closed windows and A/C on.

navegator

Driving with the windows or vents open creates a slight vacuum inside the RV. Try turning on your vent fans with windows and other vents closed and use your nose to find the place where the odor is coming from. With ours the odor was coming from the back of the toilet - an Aqua Magic IV. I sealed ours as much as I could, which helped a lot. I also installed one of the rotating vents on the top of both the black and grey tank vents, which also helped. A Few years later the rotating vent on the black tank got damaged and I replaced it with a 360 Siphon, which works even better. We can now drive with the cab windows open, although there have been a few instances when we noticed a slight odor.