190e no heat ac blowing
 

System blows for 10-20 min then nothing, shut eng off may or may not blow.
Here is what i've done
changed ccu unit,fan switch,hot wired blower motor it works, klima
checked fuses, disconnected aux water pump.

About a month ago i had same problem disconnected aux water pump and system worked
Iam thinking ign switch any suggestions?

Heater valve & blend air doors are vacuum controlled. IF you disconnect vacuum to those controls the car should get HOT.