Vauxhall Astra - Battery Light Keeps Coming On

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Thu 26 Nov 2020 10:31
Vauxhall Astra - Battery Light Keeps Coming On - guitarbloke

I've got a 2009 Astra and the battery light keeps coming on.

About a month ago, the car broke down completely - the alternator belt snapped, so I was towed home and the local garage fitted a new belt.

All seemed fine, however later that day the battery light started coming on intermittently. I went back to the garage and the bloke said it was probably the alternator so he fitted a new one.

Again all seemed fine. But the following day the battery light came back on again - sometimes it stays on and sometimes it goes off after I've turned the engine off/on again.

Back to the garage again but the light had gone back off and the guy said there was nothing he could do unless the light was on, so he sent me away. Next day the light was back on but each time it eventually went off before I could get to the garage.

Then it stopped doing it - for about 2 weeks. It started again on Monday and I got it to the garage while the light was on. The bloke said he would fit a new battery (bearing in mind he only fitted a new one 13 months ago...). This seemed to work - for about 2 hours. The light started coming back on again.

So it's now had a new belt, new alternator and new battery, but the light is still randomly coming on. Is there anything else it could be? I really can't throw more money at this, and I'm getting fed up of my local garage now.

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Thu 26 Nov 2020 12:16
Vauxhall Astra - Battery Light Keeps Coming On - bathtub tom

Possibly belt slip caused by a mechanic with oily/greasy hands transferring some to the belt.

When the light's out with the engine running, switch on all the electrics you can, headlights, foglights. HRW, A/C, fan and with you foot on the brake, rev the engine. Does the light come on?

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Thu 26 Nov 2020 13:27
Vauxhall Astra - Battery Light Keeps Coming On - Galaxy

With all the electrics switched on do your hear any sort of squealing sound? If so the belt is slipping.

It's just possible that the newly fitted alternator could be faulty. Unlikely, but still possible.

You or the garage really need to take some voltage measurements. A problem like this really needs an auto-electrician.

Edited by Galaxy on 26/11/2020 at 13:28

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Thu 26 Nov 2020 15:35
Vauxhall Astra - Battery Light Keeps Coming On - guitarbloke

Thanks guys, the missus has had to take the car to work with her today, so I can't check it until she's back now. But the bloke at the garage is currently waiting for a call from his electrician friend who will book it in, so hopefully that'll yield some sort of result.

There's no squealing or anything like that going on at all, everything sounds normal to my ears.

Given that it's got a new battery, belt and alternator now, is it likely to be safe-ish to drive (the rest of the car is absolutely sound)?

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Thu 26 Nov 2020 15:36
Vauxhall Astra - Battery Light Keeps Coming On - guitarbloke

Possibly belt slip caused by a mechanic with oily/greasy hands transferring some to the belt.

When the light's out with the engine running, switch on all the electrics you can, headlights, foglights. HRW, A/C, fan and with you foot on the brake, rev the engine. Does the light come on?

I'll give this a go tonight when the missus is home from work!

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Thu 26 Nov 2020 19:03
Vauxhall Astra - Battery Light Keeps Coming On - Nezza
Has the pulley on the alternator been changed? These can slip on the shaft and cause your symptoms. There is a good clip on a popular streaming channel called “2009 Vauxhall Astra alternator replacement” that is worth a view. (Not sure I can mention the site)
Please keep us updated with the progress.
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Sat 28 Nov 2020 10:24
Vauxhall Astra - Battery Light Keeps Coming On - sandy56

Check the battery connections- to earth, and to starter etc from the positive connection. Not unusual for the earth strap to corrode and cause problems.

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