Alternator problems (I think!?) – Accord CL7

[Kewy]

Wondering if anyone can shed some light on this…

Battery light came on over the weekend, then off again, then on again, and so on. Seemed to come on if I let the car rev higher, or brake (oddly?), but if I kept the revs down it would go off.

After a while my EPS cut out, but came back again.

I took it to Halfords for a battery check but they faffed around because they couldn't find the Amp rating on the battery as everything is in Japanese. They then took a guess, spat out a test reading saying that the battery was fine but the measured Amp reading was 2321A?! Didn't seem right?

I then managed to get hold of a multimeter and tested it myself...

– Engine off 12.5v

– Engine on 14.5v

– Engine on with lights, aircon, radio all on 14.5v

Scratching my head as although my knowledge of car electrics is pretty much non-existent, I was under the impression these readings were all okay. I then realised that I don't think the battery light was on when I tested.

So this morning I started the car and the battery light was on, tested it – 14.5v… started driving to work and the EPS cut out again, although instantly came back, pulled over and tested – 13.9v… okay, we're getting somewhere. Got to work and did a final test – 12.9v.

Does this suggest the alternator is knackered? Engine off the battery is still reading 12.5v.

Car in question is a 2005 Accord. Thanks in advance!

[Coilspring]

The reading of 12.5 when engine off. Is that straight after turning the engine off? Take another reading after 2 to 4 hours?

Sounds like alternator is intermittantly failing and the battery is helping , for now. But more tests needed for confirmation.

[Kewy]

Coilspring said:

The reading of 12.5 when engine off. Is that straight after turning the engine off? Take another reading after 2 to 4 hours?

Sounds like alternator is intermittantly failing and the battery is helping , for now. But more tests needed for confirmation.

Thanks for the quick reply.

I'll go check it again in a minute, its been sat there since 8:30 this morning.

Saying that though, I checked it before I turned the car on this morning so it had been there all night.

Just spoke to my mechanic (who can't fit the car in for 2 weeks ) – but he said it could be a belt/tensioner issue and that the belt is slipping or the tensioner is seized maybe?

[Coilspring]

Belt/tensioner is entirely possible.

But you made no comment about noises? But whether it is the alternator, or its drive/belts issue, it sounds like intermittent power supply. Battery sounds strong enough that it is substituting some power when the alternator fails, but tgat won't last for long.

If you are getting 12.5 at battery when turning it off, and after 4 hours later, then it definitely isn't receiving charge properly.

[Kewy]

Coilspring said:

Belt/tensioner is entirely possible.

But you made no comment about noises? But whether it is the alternator, or its drive/belts issue, it sounds like intermittent power supply. Battery sounds strong enough that it is substituting some power when the alternator fails, but tgat won't last for long.

If you are getting 12.5 at battery when turning it off, and after 4 hours later, then it definitely isn't receiving charge properly.

Hmmmm, I'm getting a contstant whine, louder when EPS initiates? Sorry forgot to mention that in my OP.

Yeh I'm fully expecting to break down soon

[Kewy]

Yeh just check, 12.5v and it's been sat there since I got to work this morning.

[Krikkit]

Sounds like the reg/rec on the alternator to me.

[Penelope Stopit]

I'm punting on a worn alternator brush, faulty diode, regulator playing up, bad main pos / earth at alternator or a volt drop on the ignition side of the warning light

[E-bmw]

Your voltage readings seem to be indicating both your battery & alternator are fine.

Sounds like you have an issue with your EPS which is causing the issue to me.

Can you drive it with the fuse pulled to see if that stops the problem?

[Kewy]

E-bmw said:

Your voltage readings seem to be indicating both your battery & alternator are fine.

Sounds like you have an issue with your EPS which is causing the issue to me.

Can you drive it with the fuse pulled to see if that stops the problem?

Worth a shot eh?

Even though yesterday when I arrived at work, with engine running it read 12.9v? Thats too low right?

[Sardonicus]

The EPS will fail if the alt stops charging this could be down to worn or sticking brushes like mentioned already, if you can get the alt output scoped or logged whilst driving this would give you a reliable diagnosis , a failing slipping freewheel/sprag alt pulley could give a similar symptom

[Kewy]

Sardonicus said:

The EPS will fail if the alt stops charging this could be down to worn or sticking brushes like mentioned already, if you can get the alt output scoped or logged whilst driving this would give you a reliable diagnosis , a failing slipping freewheel/sprag alt pulley could give a similar symptom

Thanks, this is exactly where I am now.

Was hoping I could resolve this issue myself, but without knowing whether it's the alternator itself, the pulleys/tensioners or the EPS then it would just be trial and error, and I don't fancy paying £200 for an alternator if I don't need to.

Looks like I best get it booked in to an auto electrician

[Penelope Stopit]

Kewy said:

Thanks, this is exactly where I am now.

Was hoping I could resolve this issue myself, but without knowing whether it's the alternator itself, the pulleys/tensioners or the EPS then it would just be trial and error, and I don't fancy paying £200 for an alternator if I don't need to.

Looks like I best get it booked in to an auto electrician

Has the car clocked many Kilometers? If the alternator has had a busy life it may well be worth your while to remove it and check the brushes, you could also replace the bearings and clean the slip-ring while it's in bits, the job is straight forward and you will be saving much cash by having a go at it, also check the diodes

[Coilspring]

Kewy said:

Thanks, this is exactly where I am now.

Was hoping I could resolve this issue myself, but without knowing whether it's the alternator itself, the pulleys/tensioners or the EPS then it would just be trial and error, and I don't fancy paying £200 for an alternator if I don't need to.

Looks like I best get it booked in to an auto electrician

You have a noise, but not sure where from, as well as the charging/not charging issue?

Remove the auxilliary belt and run the engine a few minutes, does the noise stop? Spin the alternator pulley by hand, plus the tensioner, plus any others, can you feel or hear any noises?

Should help identify the source, and the potential problem.

But it does sound like it is not charging, fully. Any noise from the belt, or obvious slipping, signs of burning etc?

Do the steps above before anything else, it may identify the issue (s) and take it step by step if so.

[mw88]

Not sure if this will be much help, but with the light going out on low revs. I had the opposite when the alternator died in my CL9.

Higher revs, the light would go out but would come back on at low revs.

Had some other things happening with the everything on the dash dying even though the car was running.

The CL9 has hydraulic PAS, but I remember years ago when the battery was playing up in an Astra Coupe, the EPS would be the first thing to start playing up.

[Kewy]

Penelope Stopit said:

Has the car clocked many Kilometers? If the alternator has had a busy life it may well be worth your while to remove it and check the brushes, you could also replace the bearings and clean the slip-ring while it's in bits, the job is straight forward and you will be saving much cash by having a go at it, also check the diodes

Yeh its over 100k now (miles), not sure whether the alternator was changed at all in its past, so may or may not be 14 years old. Whilst I like the idea of trying something new and giving this a shot, this is my daily and I can't really afford to have it off the road whilst I pull it apart and order parts etc. I'll keep it in mind though, and good links on how to do it?

Coilspring said:

You have a noise, but not sure where from, as well as the charging/not charging issue?

Remove the auxilliary belt and run the engine a few minutes, does the noise stop? Spin the alternator pulley by hand, plus the tensioner, plus any others, can you feel or hear any noises?

Should help identify the source, and the potential problem.

But it does sound like it is not charging, fully. Any noise from the belt, or obvious slipping, signs of burning etc?

Do the steps above before anything else, it may identify the issue (s) and take it step by step if so.

This is really helpful, thanks! Might even try some of this tonight if it doesn't piss it down.

Yeh I have noticed a bit of a whine that isn't normally there, gets louder when I'm full lock so was presuming its the EPS pump.

Funny you should say about smell, yesterday when I was checking it I sat with engine on and then held it at 4-5000rpm for a bit, after I could smell a bit of a burning sound but presumed it was just coming from the exhaust. Now you say it, it could have been a belt slipping right?

mw88 said:

Not sure if this will be much help, but with the light going out on low revs. I had the opposite when the alternator died in my CL9.

Higher revs, the light would go out but would come back on at low revs.

Had some other things happening with the everything on the dash dying even though the car was running.

The CL9 has hydraulic PAS, but I remember years ago when the battery was playing up in an Astra Coupe, the EPS would be the first thing to start playing up.

Interesting mate, thanks. I'm pretty sure the CL9 has EPS doesn't it? At least the JDM CL7 does. I've only had the EPS cut out so far and then come back on a couple of times. I've put a multimeter across the battery with the engine off a number of times now and its read 12.5v every time. Would that not suggest the battery is okay?

[mw88]

Kewy said:

Interesting mate, thanks. I'm pretty sure the CL9 has EPS doesn't it? At least the JDM CL7 does. I've only had the EPS cut out so far and then come back on a couple of times. I've put a multimeter across the battery with the engine off a number of times now and its read 12.5v every time. Would that not suggest the battery is okay?

The numbers seem correct - The below from the ESM manual may be of use to test further



I've done some Googley searches for CL9 engine bays and it might depend on year for the CL9, later ones may have EPS but mine has hydraulic.

Image below isn't my car, but shows the same setup.. Container with the red cap next to washer filler is full of hydraulic fluid so I'm guessing it's for the power steering!

[Kewy]

mw88 said:

The numbers seem correct - The below from the ESM manual may be of use to test further

I've done some Googley searches for CL9 engine bays and it might depend on year for the CL9, later ones may have EPS but mine has hydraulic.

Image below isn't my car, but shows the same setup.. Container with the red cap next to washer filler is full of hydraulic fluid so I'm guessing it's for the power steering!

Thanks! Will have a look at this in my lunch break. Noob question here but is a multimeter both a volt and ammeter?

Drove the car to work today as the weather was a bit naff to cycle. Battery light was on from the moment I started the car (had been sat there since Monday eve), I drove keeping the revs down and it went off for a bit but came on again when I was parking up. Felt the EPS going at one point on the journey but only slightly and the EPS light didn't come on.

[Krikkit]

Yes you can use a multimeter for both current and voltage, although current is more difficult to measure.

I'd pick up a used alternator and change it. It's the most likely culprit, and shouldn't be hard or expensive to find.

[Steve_D]

Yes a multimeter can be used for both but most will only go to 10Amp some 20 which will not be enough for a charging circuit.
Stick with testing volts. If your battery is coping with intermittent charging and still holding 12.5V then it is OK. If you are seeing 14.5 V then (at that point in time) you are charging. I'm suspecting an intermittent fault in the alternator which could be one of many things inside.
The EPS playing up is probably due to the fact it is one of the heaviest current consumers on a car so when you arn't charging it is going to suffer first.

With any luck it will fail completely and remove the uncertainty.

Good luck.
Steve