One problem related to defogger has been reported for the 1999 Chevrolet Venture. The most recently reported issues are listed below.
Heater - the heater does not work properly to heat vehicle -- there is not enough air coming from any vent, whether it be in floor, a/c vents, or defroster position. -- seems to indicate that there is a restriction in the air flow, possible an interior heater door not working properly. -- heater can be on max heat in highest blower motor position and vehicle never gets warn enough to turn heater controls down -- this is a little better when vehicle is sitting still for a long period, but it is not uncommon to have cold feet while driving. -- dealer states that all like models operate the same and that there is no problem. -- air flow through ducts is possible 1/3 that of our 1996 blazer and 1997 pick-up truck, both of which have great heaters.