Thermotop control defect - alternatives

[noertoft]

Hello and greetings from Denmark
-I hope that a little question in english here is ok?

I have en old ThermoTop mounted in my car. It is not integrated into the cars setup - it was installed later on and is controlled by the standard timer watch from Webasto.

Now the input on the controller is defect.
I have had the heater tested - and the test computer communicates via the W-bus port on the controller. Through this port the heater starts and runs with no problems.
But the analog input-port (that the timer watch is using) is dead...

So now I can buy a new (expansive) new control-unit...
But I am wondering if anybody here might have an idea on how I could control the heater through the W-bus port (like the test computer).

Any suggestions are welcome

The car is too old to have the option of controlling the heater through w-bus...

Thanks from Denmark
Jens Christian Nørtoft Bækgaard