Alternator issues

Batteries, Alternator, Wiring, Lighting, etc. (Please discuss ignition problems in the Engine category)
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Phil T
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Alternator issues

#1 Post by Phil T » Mon Jul 26, 2021 7:43 am

I have noticed recently that when lights etc. are turned on that my fuel guage reading drops, I had thought it might be the voltage regulator, but in the rain yesterday I noticed that with lights on and braking the indicators failed to work.

The battery is new and reads 12.8v across the terminals. Alternator output (2000 revs no load measured at the battery terminals) 13.8v dropping to 13.5v on idle. On load the output drops to 13.5v at 2000 revs, 13.1/13.2v at idle.

Looks like I need to look at the alternator.

Question is how are the brushes attached? Are they on a screw terminal or welded/soldered?

EDIT: I have now seen videos on line showing they are screwed - so I'll get some brushes and replace those first.

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Phil T
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Re: Alternator issues

#2 Post by Phil T » Thu Jul 29, 2021 1:42 pm

Right, alternator brushes now replaced. Cheaper than a new alternator.

I did the job without removing the alternator from the car, and once I had the socket sizes (supplied by my assistant - see first picture) the job was fairly simple.

Now have 14v output and more importantly 13.8v under load at about 2000 revs. Also the indicators work with lights, HRW and fan on under idle.

Helper was useful for retreiving the screws dropped under the car.......
The attachment Alternator assistance 1.jpg is no longer available
Alternator assistance 1.jpg

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Phil T
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Re: Alternator issues

#3 Post by Phil T » Thu Jul 29, 2021 1:44 pm

Second piccy wouldn't attach...
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Alternator assistance 2.jpg

Mike Stevens
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Re: Alternator issues

#4 Post by Mike Stevens » Fri Jul 30, 2021 9:36 pm

Hi Phil,
Another clue to failing brushes is that the IGN warning light may come on dimly at low engine revs.

It sounds like you sorted your issue by changing the brushes.

Cheers,
Mike.
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Phil T
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Re: Alternator issues

#5 Post by Phil T » Sun Aug 01, 2021 1:28 pm

Yes, thanks Mike.

Had a good run and test today prior to picking up the granddaughters, this was probably the issue when I bought a new battery earlier this year......

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