I get the message “generator does not charge battery” intermittently. Several dealers looked at this problem and did not find anything. After the car is parked for at least 2 hours, the message goes away and the car runs just fine. I recently drove the car with the message on to the point where all systems went off and the car broke down. After waiting for road assistance for 45 minutes, the car started again and the battery was measured to be at 50% capacity. Do you have any idea what is going on here?
Best regards,
Uwe Fritsch
aka the greatest fan of Car Talk outside of the USA
Yes, your generator is failing. It is intermittent which is confusing your mechanics. The brushes that carry the current are worn out and sticking a bit in their guides.
When that light is ON, the car is running completely off the battery. It won’t run long like that. Take it back to the shop and explain what happened exactly as you did here. They will check the generator and the signal TO the generator that tells it to operate and repair as needed.