So along with those usless vent lights
I also was trouble shooting the aux heater
when I would turn it on it would make grinding noise
well turns out the shaft that attaches to the
turbine in the combustion air blower sheared in half

looks like its not designed to be serviceable
so once again any src other than the useless dealer channel
"combustion air blower" vanagon
on samba and some list vendors yeilds no hits
the only part number i c are
S -B 7 S 086 075 on the side of the fan
AEG GP 80 A15 12v 6600 U/mm on end of the fan

so who is the orginal mfg do they still make these blower motors
or any one that has n working unit pmail ;)