I noticed hot air coming from under the passenger seat of my '88 Westy,
and after some investigation, found the source!  It seems there is a
duct (hole) in the left front of the battery box under the passenger
seat that is open to under the van.

If your van is missing the top to the battery box, or it does not fit
well, hot air will migrate up and out under the passenger seat.

Just wanted to report my findings as I believe I saw a previous post
describing this problem and asking what to do.

I guess the thing to do is to perhaps add some weatherstripping under
the battery door to seal it better. If you have a sealed battery, like
an Optima, would it be okay to seal up the vent duct?

Do the Vanagons with a factory auxiliary battery have a similar vent in
the battery box under the driver's seat?

Todd
'88 Westy