Wire in the glass with a wire plug into the bottom of the window frame.. is one of those holes you speak of ?
The rear heater sits next to the 3rd row of seats on the driver side .. my '93 had it but not my '92.
SUNSHINE VANS-VAN DIEGO ADRENALIN BY THE GALLON & CHASIN RACIN ONE FOR THE DIRT & ONE FOR THE STREETS '93 CHEVY G30 454 4X4 SPORTVAN EXT 146" WB '92 CHEVY G30 454 BEAUVILLE EXT 146" WB