Aircon or computer problem or ?

Le Sabre 1993
Everything started with that suddenly the aircon fan stopped working.
(The one blowing the air into the passenger room

The car can start, engine is running but the aircon fan is not working

My garage checked and found, fan ok, compressor ok, BUT identified the computer with the automatic aircon control is NOT ok.

Its difficult to find a replacement for this but finally the garage says they have found one.
They replaced the Computer unit and the Aircon controler as he said they are always to be used together.
Now with the new system even the car cannot start but in the old car the computer /; controler was working fine.
Install back the original controler / Computer let my car run again.

So my question:
Is there any theft protection inside the programming that the computer needs to get any feedback from some unit which is matched to the computer?
or is my garage crap?
or what can I do?
Any hotline of Buick can help to solve this question?

PS.:
I am in Taiwan, and its difficult to find any qualified people here?

Any idea ?

Thanks for everything even you may say forget it!

'Is there any theft protection inside the programming that the computer needs to get any feedback from some unit which is matched to the computer?''
NO! :grinno:

"or is my garage crap?"
YES! :iceslolan

"or what can I do?
Any hotline of Buick can help to solve this question?"
NO! :grinno:

Do you have Auto Climate Control? (Do you have digital display)
If so, you have a common failure on the Buick, the fan speed control module. It is located in the fan box on the firewall under the relay & fuse center. You can order one from the following links.

http://www.rockauto.com/catalog/catalog.php
RockAuto Parts Catalog

http://www.partsamerica.com/