I just bought a 2017 Grand Caravan and there is a white powder on the underside of the middle row stow and go seat area. I cleaned with vinegar but it comes back. It does not seem to have any moisture in that area and not sure what is it is and how to correct. It seems like maybe some electrical thing but not sure why it is there.

 

It’s definitely the result of either moisture or some kind of acidic liquid. If there was no reaction when cleaning it with vinegar then it’s probably not acidic.

Not sure what else to try except maybe some dish soap and elbow grease. Maybe consult an auto detailer?

What is the green tube?

 

Thanks. I did a van camper build out for a two week trip out west and had a water tank down below and used that green hose to connect to it. The white powder was there before I did this so I don't think that is what caused it (no water spilled). It sure seems like moisture so not sure how it could have gotten in there and the floor matting is all dry.

 

I will try to steam vac it and then air it out with a fan. Thanks again.

 

It certainly could’ve been there before you bought the van. You never know what a previous owner may have done.

 

Look Like ice salt residue, firiend of mine own an auto detailing shop he uses a solution of 50/50 water & vinegar in a spray bottle soak the stain with the solution let rest for a few minutes and work it with a nylon bristle brush rinse with clean water pat dry with a microfibre towel or use a wet/dry shop vac. repeat if necessary. I've use this method and it work well after the winter.