Ali_G

Hi,

My wife's 05 civic started to have some strange electrical issues. I'm not sure even where to start troubleshooting.

She originally complained that both headlights died simultaneously. I assumed that one was already dead and she only noticed when the second went out. There were no issues with the brights and the fuses were fine.

Then things got stranger ... the SRS light started coming on at random intervals while driving, stay on for a period of time and then go off. Now the battery light started doing the same. All of these issues started within the last two weeks.

The battery itself seems to have plenty of power and it's relatively new (7 months).

Thinking back, the civic has been through a lot more headlights and batteries then my Accord (01). I've replaced the battery three times in the last four years and the headlights at least once a year.

It could be battery, alternator, computer or ...

Any help would be greatly appreciated.

TIA!


Alex

ezone

(Sounds like) Needs an alternator. It is charging at far too high voltage.
The battery may be ruined as a result of overcharging.
The SRS light will come on when system voltage goes over about 16v, without setting any codes.




I had one civic come in last week running over 17v, SRS light was on, both headlights blown high and low beams, driver said the lights in the gauges went out too (but they were working when I got it) and he smelled rotten eggs --from the battery boiling it's acid.....
When I got the car the battery sounded like a percolator coffee pot gurgling, long after the engine was shut off. Battery failed it's test, and it was only 6 months old, and it would not start the engine the next morning.

A Honda reman alternator, a battery, and some bulbs got this car on the road again.

CraigW

iTrader: (1)

Yep, get a volt meter on it quickly.

Ali_G

Thank you for your responses! It gave me a place to start.

I checked the battery today before starting the car and it was at 12.4v after sitting for a day or two. With the alternator running, the voltage was 14.6-.7v at idle and didn't go much higher with increased RPM.

I jiggled the wiring harness while watching the voltage so see whether there was a bad connection somewhere but the voltage didn't vary at all. Do these alternators (original) even have a voltage sensing wire? From the diagrams I've looked at, it doesn't seem so but I'm not sure what is contained in that harness.

So from my layman's perspective that alternator looks good.

Granted, the SRS and battery lights weren't on so perhaps it would be worthwhile checking the voltage when it's actually happening but I wouldn't think this would be an intermittent problem.

Perhaps I'll put a voltmeter on the cigarette lighter circuit to monitor the voltage. Not sure what to try next...

Thanks again,
Alex

CraigW

iTrader: (1)

14.6 is perfect but maybe check it when problems occur.

The ELD will have it off/on a lot.... but look for overvoltage.

ezone

It's not like any old American alternator LOL

There's a 4 wire plug on the alt.
One is a fused and switched 12v, the other 3 go to the PCM.
The PCM has the ability to control the voltage regulator up and down depending on system needs and loads.

Hondas ELD system (USA cars) has been in use for decades, and it does gain them a little bit of gas mileage.

You have to catch it in the act. Your description says it's a problem, but you gotta catch it in the act if you want to prove it.

Yes it can be intermittent...

Great idea! Compare that socket voltage to actual battery voltage though, there might be a few tenths of a volt difference....but if the alternator acts up I'm pretty sure you'll be able to see it go well over 15v there.