The car needs a working thermostat and cooling system. The thermostat can be tested prior to replacing. Quality parts will work. Knockoff imports perhaps or not.

The heat system needs a working mono valve to control heat. There are also other components such as the push button unit and vacuum pods.

Deal with the mono valve and cooling system first. Send me a PM if you want a FSM to the 126 cars with similar systems.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.