HI

Car has not been driven for like 1 week, due to the 100 plus daily weather for weeks I cold started the engine and while parked for 5 minutes

I then pressed the auto button of HVAC control head. A/C was on but few minutes later the screen of the head showed HVAC wacko in that would cycle

everything heat, A/C, fans, defrost, etc Just keeps doing that and even pressing the off button within a minute comes back on and cycles again

Even turn the car off for like 5 minutes and starting it again on its own the HVAC keeps cycling, I can tell A/C coming on and off, changes of fans speeds, etc

Using OBD1 scanner, find no error codes tripped

Any ideas on how to debug/fix this ?

Thanks for any ideas !