I have 70K miles on my 2003 HCH 5 speed. I just replaced the 12V battery. When I did, I checked the voltage across the terminals with the car running to see if the alternator was responsible for the problem.

It measured 12.2V! So, I thought the alternator was indeed responsible for the problem. I drove to the Honda dealer with the intent of having it replaced. I got out of the car, checked the voltage again, and it was at 14V. Hmmm . . . so now the alternator is working.

I replaced the battery, and have been driving it for about two weeks. No failure-to-start problems yet. However, I have an electrical accessory (radar detector) that will give me visual indications when the voltage is low, and this has happened since replacing the battery. I am beginning to think I have an intermittent alternator problem. I am concerned that this will leave me stranded, and would like to fix it before my suspicions are confirmed by a dead battery that won't start the car.

Lastly, I have noticed that the HCH operates the alternator different than a typical car. It does not turn on the field coils of the alternator unless you turn the key to the 'start' position and the car starts. I found this out by push-starting the car when the old battery was dead one day. The engine started, but the alternator did not start charging even though the engine was running. I also learned that if I push-started it at the same time I turned they key to 'start', the engine would start and the car would turn on the alternator. I mention this because it is clear that the car does not simply turn on the alternator by switching they key to 'on', a different behavior than most cars.

So, I am suspicious that I simply have a case of worn-out brushes in the alternator. Has anybody else experienced alternator failures at the relatively-low mileage of 70K? Is it hard to remove and replace the alternator? Is this a DIY job for a mechanically-inclined person? Can the brushes alone be replaced easily?

Lifespeed

2003 Civic Hybrid 5 speed