GSA charging idiot light issue

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sonoramicommando
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GSA charging idiot light issue

Post by sonoramicommando »

Hi all,
The charging warning light started to come on since yesterday morning - it's a bit intermittent that some times it goes off as it should after start up, other times stays on or then it comes back on and off as it pleases (but doesn't rapidly flicker or anything - once on or off, it tends to stay that way for a while)
I did a quick investigation and it charges ok (high 13V - mid/low 14V) when running and the battery is at high 12V with the engine off. The commute of 15km with lights on is no problem and after 8 hours of work, starting it up to go home, again is no issue.
I'm hoping it's some earth issue with the warning lamp (as there are a couple of pre-existing dash lamp problems) but want to make sure it's not the alternator/regulator.
Can anyone help me out with the pinouts for the alternator/regulator plug/wires and any other pointers pls?
I haven't got the hang of the wiring diagram and I'm not sure I ever will...
Cheers
Sam

PS it's the rolling drum type dash board, if it makes any difference.

Hell Razor5543
NOT Alistair or Simon
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Re: GSA charging idiot light issue

Post by Hell Razor5543 »

I would guess (based on my BX problem of a similar nature) the brushes are on the way out. When they failed on my BX many years ago I had similar symptoms. I was able to source a brushes block for around £15.

sonoramicommando
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Re: GSA charging idiot light issue

Post by sonoramicommando »

thanks - do you remember how much of the brush was left compared to the new one?
I wonder if I can stretch it out to last a couple more months as I'm putting it on the market soon...

Hell Razor5543
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Re: GSA charging idiot light issue

Post by Hell Razor5543 »

The brushes were pretty much worn out. The new brushes were quite a bit longer (but we are talking over 10 years ago, so I cannot remember by how much). However, it was quite easy to fit the new brush unit, as access was good (I did not have to take the alternator off the car).

wurlycorner
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Re: GSA charging idiot light issue

Post by wurlycorner »

Also check that is outputting DC only (not AC, which indicates the rectifier is faulty)

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white exec
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Re: GSA charging idiot light issue

Post by white exec »

Note also that a working dash warning lamp (good bulb and connections) are usually necessary for the alternator produce a stable output. Dash lamp usually has a resistor in parallel with it, so that alternator still functions even if the lamp blows. Not likely to be your problem, if alternator output is good: DC, stable, and about 14.4v.

sonoramicommando
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Re: GSA charging idiot light issue

Post by sonoramicommando »

Thanks guys - I'll check if I can get to the brushes without having to remove the alternator... Hopefully the storm dies down this weekend a bit.

sonoramicommando
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Re: GSA charging idiot light issue

Post by sonoramicommando »

ok with the warning lamp on, the voltmeter shows what the alternator/battery is supposed to be doing. ~12.5VDC with motor off, ~14.3VDC with motor running.
Changed to VAC and it showed ~30, not sure what it means but probably not what's it supposed to do?.

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xantia_v6
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Re: GSA charging idiot light issue

Post by xantia_v6 »

Ignore the AC reading, your meter is not designed to read DC with AC superimposed.

I think that it is fairly safe to assume that the problem is with the brushes of regulator in your alternator.

sonoramicommando
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Re: GSA charging idiot light issue

Post by sonoramicommando »

ok thanks - looks like I'll have to take the alternator out.
cheers.

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white exec
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Re: GSA charging idiot light issue

Post by white exec »

Those two DC voltages look OK.

sonoramicommando
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Re: GSA charging idiot light issue

Post by sonoramicommando »

Is it me or the GSA wiring diagram completely useless?