My 92/960 Had recently fried two power stage modules. I had taken the car to the mechanic in desperation, but he did not come out with a fix. He suggested heat damage, but did nothing to find the cause.

I had a few replies to my earlier post to this problem, and have come with two probable causes: Heat or Alternator overcharge One of the replies was about the heat issue and I checked the flap door in the air intake under the air filter that is open to the exhaust warm air pipe. Then it turns closing that side and letting fresh air in once the car is warm up. The flap door was stuck socking air only from the exhaust hot air. This could have been overheating the manifold where the modules are placed. The modules use the manifold as heat sink. Another reply was about the alternator overcharging intermittently. I have installed a new remanufactured alternator and secure the flap door in the air filter housing open to the fresh air only. But this heat issue is still sketchy, because when one stops the engine after a good drive in a hot day, everything gets very hot in the engine compartment, including the intake manifold. The modules also even out temperature with everything else. It takes a good time once the engine is running again for the air coming in to cool down the manifold and modules. I lived in Atlanta, Georgia once where the temperatures in the summer are extremely high, the car's cooling fan almost constantly running, though the modules never failed during that time. So, at the end the alternator may had been overcharging, burning the modules.

Thanks for the team work.