Electrics: Power System Service - Urgent, you're going to die!

[oragex]

Originally Posted by Bonefishblues

Alternator giving 13.6-7 at idle.

Which year the car ? Right after a cold start, it should show close to 14.5v for a few minutes (the less, the better the battery condition), then start dropping to 13.5v In cold winter days it will drop to no more than 14.0v If it shows only 13.5v after starting a cold engine, it may mean you have the wrong regulator (brush set). These changed in 2004-2005 and the correct model must be installed, otherwise it will only put out 13.5v which is not fully charging the battery and will damage it. And in return, a worn battery will no longer accept a full charge and will force the regulator to work at all time at full load which causes the regulator to fail prematurely at the diode bridge (before the brushes are worn) https://youtu.be/Tb3ACMO_9jA

[Bonefishblues]

It's the S60 in my profile. I've had it for 6 years so I'd be surprised if it had the wrong bits fitted. The last battery lasted 5.5 years and perhaps 90k miles, so I doubt it was being damaged?

[TDIvolvo]

I had this issue, much of the helpful comments regarding the charging system still stand, but just as a curve ball here as something to consider, I had this light on my V70 and it was the overrun clutch on the pulley.

Basically it was charging to a point but under heavy electrical load the clutch would slip and therefore it could not drive the alternator with enough torque to generate the required power.

The alternator on my V70 was the self testing type, it does a full load sweep to check output, if the system doesn't see it reach the full design output level it marks the system as needing serviced, but in reality it can go on like this for long enough unless you are doing a lot of heavy electrical loading and short drives in which case the reduced charging performance will never catch-up.

[Bonefishblues]

That's interesting, thanks - I've certainly not seen anything that would lead me to believe I have terminal problems with anything - as yet, anyway.

[Bonefishblues]

Still doing it, still haven't died yet, but I can tell the battery's getting a little p8ssed not to be getting full juice - slow cranking, which isn't good. There's a noticeable ticking noise which is speed related form the lower rhs which I think's the same issue.

A couple of questions:

Chesh - how certain would you be that it's the little bush you linked before causing the issue? Nice to spend less rather than more, as always

As I'm trying to run it on a shoestring (aren't we all?) what replacement alternator brands are decent at the lower end of the market?

[cheshired5]

Originally Posted by Bonefishblues

Chesh - how certain would you be that it's the little bush you linked before causing the issue? Nice to spend less rather than more, as always

Not certain at all but removing the regulator to inspect the brushes was very quick and easy on mine so no guessing required.
Remove the battery negative lead before attempting to remove anything else as some of the nuts on the regulator are permanently live.

Originally Posted by Bonefishblues

As I'm trying to run it on a shoestring (aren't we all?) what replacement alternator brands are decent at the lower end of the market?

Rather than risking anything low end, I'd stick with a genuine Volvo one from a breaker if I had to replace.
No car ends up in a breakers from having a dead alternator so given their reliability, you're pretty much guaranteed to get a decent one.
Repairing what you already have is cheaper still.

[Millie20]

Bonefish, I'm just down the road near Wallingford if you'd like to plug it in to Vida. No charge, happy to help.

[Bonefishblues]

Thanks both, appreciated.