cashtein

hello

Im hoping someone can help me !!!!

i own a honda civic 2002 4rd aut.

I was driving around yesterday when all of a sudden my srs light turned on and soon after i lost all power in my dash ( radio, heater, flashers, etc. ). Then less than 1 min later the engine simply stopped.When i try restarting the dash needles move erratically and it wouldn't start.

But if i boost the car then it starts perfectly and also if i wait long enough it starts normally

I dont think its a fuse due to the fact that when boosted the car starts fine

At first i thought it could have been the ground but i checked and the exterier protection is damaged a bit but the wire core is fine
Could it be the battery or simply contacts ?

Today i started the car no problem and took it for a ride everything was fine but as i was pulling up in front of my house i lost the power in the dash again and turned the car off myself. Tried restarting right away but nothing ( except needle movement )

Hoping someone has had the same problem and found the solution

Thanks in advance

loyal civic owner

SpeedDownZone

check your alternator.

ezone

The alternator isn't charging.
That doesn't automatically mean the alternator is bad, that just means it isn't working. For SOME reason.

Gunner

Check your battery...the alternator charges the battery but ultimatley the car runs off the battery.. Make sure it is holding a charge..I would check battery and alternator..a local autoparts store can check them for you...Only thing that throws me off is the starting after waiting part...

cashtein

thanks for your help guys !!!

im an electrician so i did the tests myself

i cleaned the poles and connectors of batterie with small grain sand paper and then tested battery and alternator

battery alone says 12v

with car started says 13.4v

so i guess its none of the two

im guessing probably wire problem

im freaking out here !!!

ezone

Alternator belt tight? Slippage will stop it from charging under a load.

Got a carbon-pile load tester?
Inductive DC Ammeter?

You say you are an electrician: Volts aren't everything.

azalleyrats

Actually a car runs off of the aternator and NOT the battery. Once the car is started the Alternator takes over as well as charging the battery.

ezone

^^^This.^^^
The battery is only used to start the car.
The alternator carries the load while the engine is running.



In a basic sense. That's not the only job a battery does.

sdaidoji

iTrader: (1)

Eld?

Gunner

I did write that..my bad..i did not mean it runs on the battery was early here..damn.. LOL.

cashtein

@ ezone

i am electrician but i am apprentice 1 only and i dont really know about car electrics more for residential but i could do all the test if i only knew what reading i am supposed to get.

i dont have an carbon-pile load tester

but i do have the inductive ampmeter

What would you suggest i take readings on

Thanks in advance

SpdySylvrEX

This really sounds like a ground, short or loose connections

ezone

Lunch break, here's a few thoughts for ya......

It's obvious that the alternator isn't charging properly. Chances are good that the alternator is just bad, but I'd hate to replace it and find out it still had the problem, so check some stuff first.



i am electrician but i am apprentice 1 only and i dont really know about car electrics more for residential but i could do all the test if i only knew what reading i am supposed to get.

Ummm, so you are still just a wire stringing rookie, right?
Not a good grasp of fundamentals yet?No offense, I'd probably be a bit lost doing residential wiring for a while. I'd need pointed in the right direction too.


all of a sudden my srs light turned on and soon after i lost all power in my dash ( radio, heater, flashers, etc. ). Then less than 1 min later the engine simply stopped.When i try restarting the dash needles move erratically and it wouldn't start.

The alternator stopped charging and the battery ran dead while you drove.

But if i boost the car then it starts perfectly and also if i wait long enough it starts normally

Battery is dead. The boost is charging the battery when you let it sit long enough. Then you get it started, remove the jumper cables, and the battery goes dead again.
The alternator is not generating sufficient power to run the electricals on the car, so the battery has to supply that power. It ran dead.
It takes time for a battery to charge, so how long the car runs depends entirely on how much the battery got charged up.



I dont think its a fuse due to the fact that when boosted the car starts fine

Not necessarily. What if a fuse is blown that keeps the alternator from working? The rest of the car still operates until the battery runs out of juice.

At first i thought it could have been the ground but i checked and the exterier protection is damaged a bit but the wire core is fine
Could it be the battery or simply contacts ?

Lots of "could be" stuff is possible. Test, don't guess.

Today i started the car no problem and took it for a ride everything was fine but as i was pulling up in front of my house i lost the power in the dash again and turned the car off myself. Tried restarting right away but nothing ( except needle movement )

Same scenario, you haven't fixed the problem.
--
--
--
--
--
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Start with a fully charged battery.
Make sure the alternator belt is tight.
---
Turn the ignition key to ON, don't start the car. Is the battery/alternator/charge/whatever warning light illuminated?(Y/N)
If no, go directly to wiring checks and skip this below...
--
Does the same idiot light turn off when the car is running?(Y/N)
Does the same idiot light come on while driving?(Y/N)
--
--
DVOM on the battery terminals. Ammeter clamped around ALL of the cables on ONE battery terminal. Ground terminal is usually easier to use.

Start the car, note the readings on both meters while cranking.
Run the car, note readings.
Turn on high beam headlights, rear defogger, high speed fan on max A/C. Note the readings on both meters.
Raise the RPM to 2500 with all those accessories on, note the readings.
Let it idle again, note the readings.
At some point, it should be obvious that the alternator is not able to keep up with the demand.
--
Again: Is the alternator belt sufficiently tight?
Are the alternator mounting bolts tight?
--
--
--
Wiring checks:
Unplug the 4 wire connector from the alternator. DVOM, key ON, engine OFF...Is there 12v measured on the blk/yel wire?
The other 3 wires go to the PCM. What voltage readings do you get from those?
Is there 12v at the BIG wire on the alternator? If no, check the 80 amp fuse in the engine compartment fusebox (the car shouldn't have started at all if it was blown)


Next might be voltage drop checks......

cashtein

@ ezone

Thanks a million

Not a good grasp of fundamentals yet?No offense, I'd probably be a bit lost doing residential wiring for a while. I'd need pointed in the right direction too.

none taken, youre totally right

Not necessarily. What if a fuse is blown that keeps the alternator from working? The rest of the car still operates until the battery runs out of juice.

that taught hadn't even crossed my mind thanks

There is a snow storm in my area right now so its kinda impossible.But tomorrow if its calms down i will do them and keep you posted.But i will go test all my fuses inside the car now.

Thanks again for pointing me in the right direction

ezone

YW.
I was on lunch and just tossed a bunch of stuff out there somewhat randomly.
Not sure if it's the right direction since I can't see and diagnose what the car is really doing, but it's some direction at any rate.

btw: I bet I would try to do house wiring like car wiring, that's just how I think now. Probably not quite up to code, LOL.

SpdySylvrEX

There is a fuse for the altenator under the dash that's under the steering wheel. I believe it's a 10A fuse.

cashtein

Alright here are my readings

amp volt


car off 0.01 12.4

turned key 0.24 12

start car * 9 * 13.2

'' + hazard
heater defrost 6 11.5
radio wipers
etc.

no rpm Gage
so estimated 9 11.2
2500 rpm
+ wiper...


** amp. diminishes slowly for about 2 min then stabilizes around 6.5

Checked fuse for alternator ( # 4 ) and it is good

Took it for a ride about 1h and had absolutely no problem don't know if maybe cleaning bat. poles and connectors + fixing up ground fixed the problem

i am wondering if the slow drop in amperage could mean that my alternator is dying

No time to do the wire test now but i should have time to do it this afternoon will keep you posted

Any hypothesis explored and discarted is a step closer to finding the problem + i am learning a **** load of things.Just fixed the drl problem i've been having for the past month by re soldering 10 solders on the drl relay

Thanks again

cashtein

Never mind it happened again

but when i lost the power in the radio and all dash stuff i reved the motor and it came back temporeraly.

Probably the alternator then no ?

a step closer to solving the problem !!!!

ezone

Good enough static voltage on the battery.Umm, key on probably uses more than just a quarter amp.

Ok, we need the plus or minus on the amp reading. Right here, we know all the current is coming OUT of the battery, so turn the amp clamp to read negative (discharging the battery). Note this in all amp readings!
Need to know if that is neg or pos amps.
I'm guessing it is positive amps, since the voltage came up. The voltage rise means the alt is doing SOMETHING. Still a little low on volts but it is higher than the value of the battery. It is carrying the load of the car and charging the battery.......
Now, how much work will it do?
Volts dropped, amps should have gone negative. At this point the alternator can't keep up with this amount of load, so the battery is having to do the job. Battery is discharging again.
We are done with that, I already knew the alternator can't keep up.

Now: Was the alternator idiot light ON at this point?
And again STILL: You haven't said if the alt belt is TIGHT. A loose belt will let the pulley slip and then it can't produce electricity when demand is high.


If the belt is tight, then I think you need an alternator.



------------------------------------------------
No, and yes. No the slow drop doesn't mean that, but yes the alt is dying (not charging). Read on...

If you had clamped around all the cables at a battery post, you are reading what is going INTO or OUT OF the battery ONLY... and a fully charged battery will not suck a bunch of amps, so your reading is lower than with a low charge in the battery. A battery in a low state of charge will accept more amps at a given voltage.

My bad, I forgot about this.....when we do a load test with a VAT tester, the load is clamped to the posts, so the amp clamp reading is what the alternator can put out minus the load of the car itself.
DUH on my part... You are using the car as the load so I gotta rethink this...


Move your ammeter to the big wire on the alternator...

(anywhere on the wire--preferably more than 3 inches away form the alt because, and be aware of this, that close proximity to the alternator with an inductive ammeter can and will give false readings due to the magnetic field around the alternator....the inductive ammeter works on magnetic field principles to measure. KNOW your tools!!!),

Measure amps directly out of the alternator and load it with all electrical consumers turned on full blast.
Neg or pos won't matter on this check, the alternator is a producer, not a consumer so I already know what direction the amps are flowing.

I bet it won't produce more than 30 amps.

Next should really be a voltage drop check: one DVOM lead on the alt charge stud for the big wire, and the other on the pos post (the actual post, not the clamp) of the battery. Run it, load it, check voltage... shouldn't go over 1.5 volts, and this can vary with the amount of the load.


Same test for the ground side. Alt case and neg post. run it, load it, read it. Shouldn't be more than one volt at max charging load.



If the belt is tight and the wiring is tight, then I think you need an alternator.

ezone

You still haven't fixed anything.

Is the freekin' belt tight?

cashtein

sorry
amp reading is positive

will take readings and check tightness of belt first thing tomorrow

with amp meter on the big wire on the alternator...

alternator idiot light never comes ON only the srs light ( 1-2 sec then off )


thank you so much for your patience and knowledge

ezone

Positive amp reading? Not on all of the steps it wasn't. Not if you had your clamp around all the cables on one battery post....properly.

The amp readings HAVE to be both positive and negative--- at each step above, your test results cannot have been all positive.
I explained exactly what your ammeter was doing at every step above. If you did it right, then you should have seen exactly what I said.
The difference is quite important.
Learn theory and stop being a rookie.

GRRRR. Sorry, I am a lousy teacher, no patience.

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Belt tension check should have been at the top of the list.

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The light: Does it come on with the key on, engine not running? (It should be on when the alt is not producing electricity).

Or did you really mean never ever?