I have a 1997 Civic that has been having intermittent problems that I’m not really sure what to do with. I’m not great with cars, but am confident enough to do some troubleshooting and handle simple repairs on my own. I’ll do my best to give a detailed description to what’s going on. I don’t drive my car often, so I kind of discovered these problems over a period of time. My check engine light is not on.

The initial problem was a rough idle when stopped at a light or when traveling at low speeds (<20 mph). Lately, this has been happening when traveling at higher speeds as well (up to about 40 mph). The rpm gauge fluctuates and, when moving, the speedometer occasionally drops to 0 mph and then jumps back up. Once or twice, the engine has stalled out due to the idle getting too low. When driving at night the rough idle is accompanied by flickering headlights and my CD player occasionally resetting (the display goes blank and then turns back on in 1-2 seconds). It seems like an electrical surge to me. Last night in my garage, I noticed that turning the AC on/off affects the surging as well. For example, with the AC off I was experiencing a rough idle and headlights flickering a little. When I turned the AC on while this was happening, the idle revved up and the headlights got brighter and then the engine stalled out and the battery died. Again, what happened could best be described as a surge of sorts.

As I mentioned, the rough idle and “surging” are intermittent. Last night, immediately after my car stalled out due to my turning on the AC, I restarted the engine and it ran smoothly. No rough idle, and no headlight flickering. However, when the engine is running “normally”, I’ve discovered that my battery light comes on, but only barely. During the day time it’s not noticeable, but when driving at night you can see that the battery light is barely on. My battery is less than a year old and I’ve never had to jump-start the car even though this has been happening for over a month. It’s almost like the alternator is working, but only partially…not even sure if that makes sense.

If anyone out there could offer some insight, I’d appreciate it.

 

if the battery light is coming on that means the alternator is poopin out on ya. the light stays on when the engine is dead but the key is on. meaning theirs no charge, then turns off once you start the motor.

 

I cleaned the idle control valve a few days back and that seems to have fixed the idling problem. And with that, the electrical "surging" has stopped.

Regarding the alternator/battery light, I was always under the impression that the battery light would be either on or off. With my car, it's in between the two...not even noticable at times. I tested the system and here are the readings:

Battery w/car off - 12 V
Car on - 14.2 V
Car on w/full AC - 13.7
Car on w/full AC + headlights - 13.4

Is it normal for the voltage across the battery terminals to drop when you start switching on different circuits in the car (AC, headlights, etc.)??

 

I know 98 civics are know for electrical problems. We are on ignition swith # 3. Check alternator voltage with engine on. I think it should be over 14 volts. If it does it ain't the alternator. Jiggle key while running see if strange things start to happen. It is wierd sometimes it feels like a nut sometimes it don't. If call stalls while driving Jiggle key in switch.

 

The voltage with the engine on and various electronic circuits running are listed above. The alternator puts out over 14V without the AC or headlights on.

Jiggling the key while running does nothing and the ignition switch is just a few years old. If you have any other suggestions, I'd appreciate it.

 

It appears that the alternator is working properly, other than the warning light. It's normal for voltage to drop trying to supply heavy loads at idle rpm. When you rev the engine it should go up.

The wire for the light could be damaged or shorted behind the engine in the "fuse 15 problem" that affects 1996 - 2000 models. Get underneath the car and inspect the wiring. Also you could unplug the plug from the back of the alternator and turn the key on, the light should stay out completely then.

 

I know this response is really late, but I figured I'd give an update just to close this loop.

Since I cleaned the idle control valve, I haven't had any idling issues, so that appears to be the culprit.

My battery light still comes on very dim whenever I drive the car, but my battery still hasn't died after several months of this happening. The voltage across the battery terminals seems to be okay, so I'm not exactly sure why this is happening. I'd like to resolve the issue, but since it doesn't appear to be affecting my car's performance, it's not a pressing matter.

 

its not a pressing matter. but if that light turns on bright and wont turn off. get worried and try to get to where u need to as fast as you can. my alternator belt snapped off on a nice hot sunny day bout 4 miles from home. battery lite wouldnt turn off. so i kept driving it as fast as i could home. turned it off then went to restart it. starter didnt even click and dashboard went dim. you dont want that happening to you at night? id fix that wire. that battery icon is a indication that your alt is failing on you...