[trebor]

Kamil , Its starting and stopping because its working as a supplementary heater so each time you switch the car off it will go off after completing its shut down procedure, and when the car is started again it will come back on if the temperature is 5 degrees or below.

If you do as Steve suggested and cut the wire for the supplementary heater you will have total control with your remote so it is on when you tell it to be on and off when you tell it to be off, no more stopping and starting with the engine on and off

The ATC is not clever enough to switch itself on so you have to leave it on the setting you want the day before and once it then gets the signal it will come on the last setting you made

Because you have the early model you might find that your ATC switches on 5 minutes after the heater starts which it is intended to do so it doesn’t blow cold air in the first few minutes of combustion, the later model 98570B starts the ATC with the heater so it does blow cold for the first few minutes until the heater starts to get the coolant warm

So yes do 2 of these as you suggest:

Remove the “shutting down” wire when I start the engine ?
Remove the auxillary mode by cutting temp sensor wire ?

Then wire the remote into either pin 1 or pin 3 as they both take 12v and the only signal your heater will get will be from your remote fob and you will have total control