Hello everyone, I just found out Ms. Civic has an abnormal behavior during night time. The problem was onboard lighting (interior, head lamps, dashboard light) tend to become brighter during in gear gliding(go down the slop with out gas). But once I hit the clutch or acceleration pedal all lights will become dimmer and as the way it is all the time.
I have 3 suspects in my mind:
1. generator is dying
2. battery is dying
3. voltage regulator is dying (if Ms. Civic has one)
So far I think I can almost rule out dead battery. Since to start Ms. Civic in the morning (form -4 to 13 Celsius) is relative easy. In most of the time the engine will start by give it a .3 sec starter burst, and very rarely I need to run the starter twice. The sound for the starter shows the starter is working at proper condition(right voltage). Terminals connected to the battery are all secure. I guess that is a indication the battery is ok.
And now it is down to generator or voltage regulator. However, I think the voltage regulator is OK, since a failed voltage regulator can only cause voltage supply exceed operation voltage. and whether or not Ms. Civic has this device still remain a question (for me).
Hence, I guess the generator may have problem. Since the location of D17A1 generator is relative remote (under a hydraulic pump I guess). I can not have a full view of the generator. I found some rust on a internal component at the back side (fan?!), and all terminals connected to the generator are secure.
Therefore, I want to ask people here if there is any other thing can go wrong but I failed to realize. And if there is any countermeasure need to be taken? Oh, and IMO the head light is very dim during driving, the acceptable brightness can only be achieve during gliding.

 

You may have faulty windings on the alternator that lose contact when reved up high and/or subjected to higher load. I think VR is integrated part of the alternator on these cars.

 

Check charging by measuring battery voltage with engine idling (should be 13.5 or more). Maybe there is a loose wire leading to the alternator, shake them around and see if voltage changes. If not I'd agree the alternator is worn out. Voltage regulator is inside the alternator.

 

Yeah, that could be the case, since cars in the north are always corroding in the winter. It is possible some of the insulator layer on the winding come off. Thanks for the help!

 

Thanks, I think I will grab a multimeter after this turkey weekend.

 

Hi, I have check the voltage. And it is 14.2. So... I guess might be the voltage regulator was out?!

 

14.2 is a good voltage, shows at that moment it was charging OK. This is an intermittent problem though, so you have to catch it when it is not working.

 

Well, actually to duplicate the problem is easy. Every time I glide down a slope in gear, the light will get brighter.
The battery voltage is OK too. 12.5, not at its prime but still Ok.
So, I assume when I glide down a slope in gear, the voltage form generator is more than 14.2.