I had a kickdown trace vaporize on the Klima circuit board. The reason ended up being that the wiring to the solenoid had torn insulation, so when kickdown was engaged it sometimes created a dead short. That was tricky to diagnose, but at least the repair was easy. Knowing that can happen, test to see if there's a short to ground in the kickdown circuit. If there is, fix the wiring before you waste another Klima.