1993 300e 104 engine
 

I'm having to install my 3rd control unit in this car in less than 2 months. Ignition drivers are going out, and not the same ones each time. We have a new engine harness in the car. The owner has noticed that when this happens (the car begins to run poorly)
the heater fan ceases to work...can't imagine what connection there is there. Would like some feedback on what could possibly be killing the ignition system on this car. Thank you.