How do you switch between holding tanks.

jaydub74 wrote:
This might be a dumb question.

I just purchased a new trailer and I noticed on the display panel it has two black tanks and two grey tanks. The exterior only has one drain location, with two pulls, one grey and one black.

So two questions. When we use the trailer and one tank fills does waste automatically switch to tank two?

And when I drain the tanks, do I just pull the grey and black levers and that will drain all 4 tanks or do I need to do something further?

Thanks