blogman

2001 Honda Civic LX Manual transmission
Vehicle history before I got it:
Had 2 batteries, 1 alternator, alternator pigtail replaced within the
previous 18 months.(would appear chasing after same issue I am seeing)

What I have done:
Battery was toast...9cca
-Installed new Battery
-Alternator(honda brand) was removed and bench checked by Honda dealership and NAPA and checks out good (only 1 year old)
-Replaced Ground Cable from battery to body to engine.
-Positive cable from alternator to fuse box shows no dc voltage drop - terminals clean and solid
-confirmed good pigtail plug and splices were good and solid(soldered)
-Swapped out ELB module (electronic Load Balancer) - no change
-fuses ok and show ~12volts (both engine and dash fuse panels)
-Vehicle has no special sound system or other addons

Symptoms: Test Drive
At pre-Startup battery shows 12.6 dc volts
-Start engine - running - no battery light
-SRS light is on and Maintenance light is on - (OBDII/EOBD scan shows yellow warning but no specific errors?)
-Battery light comes on after 1/4 mile,
-after another 1/4 mile battery light starts to rapidly flicker
-Flicker not seem effected by rpm, or adding load(fan, lights, etc.)
-I pull back into shop, while running, battery light flickering rapidly
-Show 16.9 DC volts at battery

Engine off - battery 13.6 dc volts - so battery did charge
but:
1- no battery light to solid battery light to rapidly flickering battery light
2- these charging voltages seem to high (16.9dcv)
3 -System is frying/eating batteries

HELP!!

Wankenstein

I've never experienced your car's issue so the following is a WAG:

Is the alternator an OEm or aftermarket? Sounds like a voltage regulator issue. From what I've read for 7th gens the voltage regulator is part of the alternator. Another thought is failing alternator diode(s) however, (also, from what i've read) usally cause a voltage drop and parasitic drain.
Under load the alternator puts out between 13.5 and 14.5 volts so, 16.9v is excessive.

Hopefully, Ezone or others with more experience will chime in and provide some answers.

mikey1

this is correct,

you need to replace the alt,

bench testing it means nothing

ezone

Needs alternator.

If no codes it may be on because of high system voltage, and will go out when voltage is normal.
If there are SRS problems, the light will stay on after alternator is fixed. Find and fix the problem.
Change oil and reset
That cannot scan SRS or maintenance.

blogman

This is a OEM Honda alternator
Both Honda and NAPA told me they did full load tests
and that alternator was good.

How am I going to convince Honda that
alternator is bad as still under warranty?

replace the alternator was my first instinct
which is why I took it to Honda to check.

ezone

It has to act up while it is being tested.
Obviously, it can test as good until such time as it acts up and presents a problem.

You say it has to be driven a quarter mile (or more?) before it acts up.
That probably won't happen on a bench test, it has to be on the car.
That probably won't happen sitting still in the garage with a tester on it either.
Engine heat and heat from loading is probably a big factor in getting it to act up.


Communicate what needs to happen. Tell them to connect a volt meter and drive around until the voltage spikes high.....
Troubleshooting that high voltage (if correct) will tell them the voltage regulator is bad and repair or replace the alternator.



Here's a clue: If the charging system goes above 15.2v the SRS system can turn its warning light on without storing any codes.
If there are already fault codes in the SRS system, then someone may not believe the above.

I know this because I've had to deal with it. Not everyone in shops has had that experience or had to figure it out....or cares enough to.

blogman

Update: I took the car to the Honda Dealer - they agreed alternator was bad and replaced - free of charge

But after replacement they also got the high voltages
They did a diagnosis for $110

Found that who ever had changed the alternator pig tail
before I got the car had mixed wires up
Honda dealer fixed as part of diagnosis charge

So got car running - yea!

Surprisingly pleased with this dealers response - this coming from one who
tries my best to stay away from dealership repair shops.....

Thank You Ezone

ezone

I couldn't have predicted that sort of mess from my recliner LOL, I would not have thought it could be that difficult to get 4 wires matched up.

Glad you got it straightened out, and glad you got a dealer that could treat you decent.

mikey1

oh stop making excuses ezone, is this not you?