Removal and installation the heater (Audi 100 C3)

Disconnect the wire from the negative terminal of the battery.

Disconnect the control unit.

Disconnect the glass heating hoses.

Remove the wiper arms.

Remove the protective cover.

Remove the fan duct.

Disconnect the plug connector.

Disconnect the heater cable harness from the instrument cluster.

Disconnect the fan mounting belt.

Open the expansion tank cap.

Clamp the heater hoses.

Disconnect the hoses from the heat exchanger.

Remove the heater.

Install the heater in the reverse order of removal, then remove the air locks from the cooling system.