Odd acting battery light

[1995Craig]

Hi all, hoping the experts on here might have a quick answer for me as in 37 years of all kinds of cars I've never seen this particular issue. My '95 AE101 Seca has 301000 klm's and has just started flashing the battery light at me while driving to work. there is no relation to revs [high or low] or to load [ lights or not] and the light doesn't really come on a lot it's sort of slowly brightening then going out or just appearing then going away. never lasts more than a minute or so and was visible a total  for maybe 10 minutes of a 40 minute drive. When I get time I'm planning to check belt [Okay at last service], connections on alternator and battery [ no signs of corrosion ]. Does anyone have any ideas \ suggestions please??

[ke70dave]

Got a multi meter? 

Put it across thw battery with the engine off and once again with the engine on.

Should be 12ish with engine off and 13ish with engine on. If its not 13ish your alternator is the culprit:)

[Banjo]

.Most likely the brushes on the slip rings have got to the end of their life and are not making constsnt contact with the slip rings occssionally. Easy fix. Cheers Banjo

Edited November 18, 2017 by Banjo

[1995Craig]

Hi ke70Dave & Banjo, thanks for the prompt replies I will be checking this arvo as per the first post and what you are saying adds up, age and wear from the sound of it. I figured a recon alternator or even 2nd hand would probably be an easy fix as I've never pulled an Alternator apart but will let you know how it goes as time permitts     [ Kids wife & shiftwork usually get in the way ] but there's always the 112 auto as a backup if need be :-)

 

Edit after finding 20 minutes spare. I found a little corrosion on the bolt shown uncovered in this pic so I've loosened \ removed and RP 7 'd all the connections I could reach \ find and when I ran the multi meter she was 13.25 Volts off and 14.45 running so the battery's healthy and at worst it would appear to be banjo's brush issue now to research how to's on remove & replace those buggers but at least we can work on these old girls without a computer degree eh?

Edited November 19, 2017 by 1995Craig

[Big G]

The values measured across the battery mean the battery is healthy but also that the alternator is charging that is the 14.45 volts value....have u checked the dssh light since u cleaned up that connection?

[Banjo]

Your alternator is one with an inbuilt regulator. (that grey plastic bit on the back of the alternator).  Only 2 screws to remove to take it off, after disconnecting the battery.

Brush assembly & regulator are all one piece.  Easy to remove & inspect.  Brushes are easy to replace.  With the regulator removed, have a look inside the hole, if possible, & take a look at the condition of the slip rings. A quick turn with a bit of 400 wet & dry emery paper will usually have them shiny again.

P.S.  I did it once on the side of the road.  Brushes were worn. Stretched the springs a bit & put it back together again.  Got me home OK.

Cheers Banjo

Edited November 20, 2017 by Banjo

[ke70dave]

Depends how enthusiastic you wanna get with DIY.

With alternators and starter motors i have always just dropped them off at the local auto electrician and got mine either rebuilt or bought a change over unit. If you do that there is a good chance it will last another 300,000kms:)

[1995Craig]

Hi guys, thanks for the replies. Yep still doing it with the intermittent on \ off light, that's why I think Banjo's right & it's worn bushes:-) I'm still working out how to - new one on ebay only $187,  2nd hand from local wrecker with 3 months warranty $65 [ & then refurb old one } haven't talked to auto electrician yet so all those options are good & possible. Spare for the 2000 ae112 wouldn't hurt anyway & I believe they're the same one. She's still taking me to work every night no worries so all good so far. 

[Banjo]

Quote

Yep still doing it with the intermittent on \ off light, that's why I think Banjo's right & it's worn bushes:-)

They are brushes, not bushes.  A bush is a bearing in an alternator context, where a brush is something that "brushes" as it slides/rubs on the slip ring.  If you tell your auto sparkie you need new bushes, he'll quote you quite differently, than for fitting new brushes.  Brush change/replacement is easy, as long as the slip rings are in good nick & haven't gone slightly oval.

Cheers Banjo

Edited November 20, 2017 by Banjo

[1995Craig]

Yep sorry missed the r out little rectangular carbon bricks with tail wires but looks like they're in a plastic housing on these alternators right??

[1995Craig]

Just to update fella's, the issue was slowly getting worse and local auto electricians ranged from flat out busy to ridiculously expensive so I grabbed a 2nd hand one from a wrecker [ 3 months warranty] planning on getting mine rebuilt & would then have a spare for the boys 2000 model sedan BUT when I got the old one out it is really noisy with shot bearings and something grating in the back of it [ probably just the worn out brushes] but when you spin it without the belts tension on it really woeful noises ensue so I'll wait till some days off and pull it apart then price new parts but maybe just retire it and get another 2nd hand one if need be,  the fella who pulled the part at the wreckers told me the car only had 170000 klm on it so I should get some usage out of  it.

Edited November 22, 2017 by 1995Craig

[hichamaziz]

have you checked the dssh light

[1995Craig]

All done it was the alternator no issues since replacement.