[Ccass]

Rear window defoggers were the early form of removing steam or moisture from the rear window ( inside) and should not be confused with the later available defrosters. The defoggers were based on the movement of air across the glass, similar to the front defroster of the heating system. The defrosters were electrically operated and could also defrost ice on the back glass, something the defogger could not do as its source of air is from the rear and normally is not warm in the winter. In the summer on a steamy day, the defogger can be most beneficial for seeing out the back
The defogger was first introduced in the GTO in '64. The '64 and '65 models were exactly identical in that they mounted in exactly the same position on the (mesh) package tray and both had their two speed switches mounted under the left side of the dash. The basic defogger did not change in appearance throughout the model years except for the switch appearance and location.

[Ccass]

Rear window defoggers were the early form of removing steam or moisture from the rear window ( inside) and should not be confused with the later available defrosters. The defoggers were based on the movement of air across the glass, similar to the front defroster of the heating system. The defrosters were electrically operated and could also defrost ice on the back glass, something the defogger could not do as its source of air is from the rear and normally is not warm in the winter. In the summer on a steamy day, the defogger can be most beneficial for seeing out the back
The defogger was first introduced in the GTO in '64. The '64 and '65 models were exactly identical in that they mounted in exactly the same position on the (mesh) package tray and both had their two speed switches mounted under the left side of the dash. The basic defogger did not change in appearance throughout the model years except for the switch appearance and location.

[Todd]

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[This message has been edited by Todd (edited 07-18-2000).]

[KellyKlein]

The grills and basic defoggers are different per year, also. The 64-65 used a wider grill than the 66-67.
The motor is the same from 64-67 and is all black.

64-65 switch is tempest only, 64-66 big car switch is the same as 66-67 GTO but will not work in the 64-65.