You probably have a broken connection at the back window. First look at the connections on the glass. The wires on the glass lead to a plug. See if it is unplugged or if the connection has been torn off the glass. There may be two plug's. If they appear to be ok then check the wires on the glass. They are glued on the glass surface and if something has scratched them or cut the connection at some point it's just like cutting a wire.
On the dash below the headlight switch
Probably the rear defrost indicator.
Yes. Yes, on the dash there should be a button with a picture of a square with lines going through it when you push it the light will turn on and should work right away.
Its under the dash on the drivers side in the engine compartment.
Below the dash on the drivers side fuse box. Marked DEF
If you are having rear defrost issues, I have a 93 also. There is a rear defrost relay that is constantly going bad. It is located under the driver side dash above the gas pedal. This shiny metal box was the cause of my failure. It may be yours to. There is also a fuse for the rear defrost in the fuse box. Check these and check the contacts out back at the rear window also.
No, the rear defrost is just an electric grid on the rear window. No air movement involved.
Bulbs may be blown.
The relay for the heated rear screen on a Golf MK4 should be just below the heater controls on the dash. Look for a button that says rear defrost or something to that effect.
its under the drivers side dash not sure wish one it is but check them all and replace them as needed
Rear defrost - One side or the other, screws to body at back glass.
The 2005 Chrysler 300 rear window defrost relay switch can be found beneath the drivers side dashboard. The rear window defrost relay switch will be near the center console.