Charge light on - alternator brushes OK?

[Bolin]

Hi all

Charge light came on, only a mile or so from home.

Dived in and removed the voltage regulator (CDT) but the brushes look fine to me. Your thoughts?

https://lh3.googleusercontent.com/sC49fgVWphVBuAKI133hxOO15YGctjHuAVt9yEXL4vH8QTk6TS naC_4QP_5KFgDKvnCD-tKtHeiV_jkm9gZnzOxAzRjNwUCXscEWf3AvK-gB330j7OJh3me3g7yqdkk18IlvH9uL1g=w1029-h772-no

Waiting for camera battery to charge so I can get a good photo of the bit they rub on, but that looks OK too. Will post pic as soon as I can.

If both are OK, I'll check the connections, and then the wiring continuity. Erm, then what?

Thanks, Bolin.

[marinabrian]

Hi all

Charge light came on, only a mile or so from home.

Dived in and removed the voltage regulator (CDT) but the brushes look fine to me. Your thoughts?

https://lh3.googleusercontent.com/sC49fgVWphVBuAKI133hxOO15YGctjHuAVt9yEXL4vH8QTk6TS naC_4QP_5KFgDKvnCD-tKtHeiV_jkm9gZnzOxAzRjNwUCXscEWf3AvK-gB330j7OJh3me3g7yqdkk18IlvH9uL1g=w1029-h772-no

Waiting for camera battery to charge so I can get a good photo of the bit they rub on, but that looks OK too. Will post pic as soon as I can.

If both are OK, I'll check the connections, and then the wiring continuity. Erm, then what?

Thanks, Bolin.

Look good to me too, what condition are the slip rings on the commutator ?

Brian :D

[Bolin]

Thank you Brian.

I think the slip rings look fine although I'm no expert - will post photo once camera battery is charged.

[Mike Noc]

Could be a wiring fault Colin. Chris had a similar problem here:

https://the75andztclub.co.uk/forum/showthread.php?t=203716

[Hootbleet]

I had a similar issue last year and the light is still on, although you can’t see it cos of the black tape over the top of it. I changed the everything, followed all the wires every where I could but couldn’t find the cause of the light. I’ve probably done over 30k with the light on now.

I’ll probably get wrong of Brian now!!!


Sent from my iPhone using Tapatalk

[marinabrian]

I had a similar issue last year and the light is still on, although you can’t see it cos of the black tape over the top of it. I changed the everything, followed all the wires every where I could but couldn’t find the cause of the light. I’ve probably done over 30k with the light on now.

I’ll probably get wrong of Brian now!!!


Sent from my iPhone using Tapatalk

I'm heading through the tunnel to chin you now Graham :fight:

Brian :D

[Bolin]

https://lh3.googleusercontent.com/V3wuPWmsgmAQCwTZLwuFtkPAcHfNYe861gmaf4khK8I1qic4Ej B0v0RtycvU12WxcCkBK5EFxFeFXm8-8CByFkiM055txCDrVkwqGc3e22VuWAmQOKYEuahpo1rJ1JSDVn 0wGTQ26UFeQmJ0Cbqjw6Dd1oCsl--3sff2lhdfEb_RkAmjHoasVYA-3kQGQFXgET6W93zvuRT2eKbXCBfrTZSYJObecnbSpbv1brbzcZ Oriw3ARUYFqCKCrK3bwS7S6DHwXmZpyJ_KXf1uac4BbzMk7stD agoa82QXBBU-LvPvkunX_6Eij_6kghCJ5kXkqJqUpgSx5DNP7H3joPOE6oayZm XuvnaxM03_BtHQ-aEBjBezpX6PIVvQ9uTT4hqdaRSE2s6yVDJyLC5Mo9OyePOxZiK B2B3LDsDKoIs6E1hi08DV6OMXpTZWMtI6GCq5gcBg94X4cvsmG G8O62z02eXznBNZfSdWzPCnl0NE9Hy_9ZYUwycWt1vgejOqdDZ d0LYFQizzfJiKatRzLnxKin5aKIFokRO2izRa3T8b8I0F9sobh xhqTL9IRsPOxoDoaUz5IcZe6KLlRpTE12p69TEmUXVWHpFJWKE Czf3JaQ=w962-h641-no

I think that's OK? Although one side is more worn. The brushes appear to be equally springy.

Fuse 36 was OK (earlier fusebox). Wiring under headlamp inaccessible to check.

Forgot to engage brain so I didn't even measure voltage at the battery before dismantling the alternator!:duh:

Also, managed to remove regulator without removing air intake (because the screws just kept rotating).

[COLVERT]

After your wiring and connector check we could do with with a voltage reading at the battery with the engine ticking over.---;)

[Bolin]

I think I have fixed the second picture now....

[Bolin]

Gone again - will try again tomorrow....

[Bolin]

Another pic of the brushes, hopefully this and the pic of the slip rings will work this time.
https://lh3.googleusercontent.com/AmyO0gbo-cjAQTPDtnkcVkrU3FXZhHt_ZhzWkTQqH9MzSgkxSPTsq9PBVzq B250OuLkZQx9QKSbDrGHNjZY8c8Fn4c93sJgxAxkkGnVIOPUNY 9j8GCaEIi67cC1BkSEIE8c3HJICyHTr7dDE8IOyoNgIID5FIT0 f6X0QtqEehdahASmjLdUDbGh7srnmndNMg9Kt8gymDeQcFJJJ9 bxYx8E0ErCfQRXYOmWHoLw0Kr5y737sh8oD2_VwDniO2NkjXeE 1bLP5kuZKIga88TT8iNogm3qwhsMSBd6S1z2LTITjVvVBafctp U9bTV-TJllZjxl8dRHNzqKEoq6IQFOMY0wgxePNjPX0axw0fyTT-0iM2c4BLwraC1BkU6h8kcpo8osqQO13FEEAwlQIu20KWiBbQZs s6EAwfGy2CK5zQ0CIL-zNR8kHK1WwEexBhK9HrRS1Q3n4UVLcVaot22I00vKWgh4isBcK 5_KswE8n4jyWqNbYxOJnUDMY401IrkKFnXiF_9cWjrFu2aklRG Ig0wBftIFQ00xO5JsCZd9r06kagSi3R-OHBbChZwVRcW1paHjNJTFGbG_eS2-FyElV5TEHLkfOna9vKfZa6RrwwQ=w1229-h823-no

Put everything back together, battery voltage was 11.1-11.2v at idle.

Any thoughts on the last two photos?

Otherwise, not sure what next - check wiring for continuity?:shrug:

[COLVERT]

Those slip rings don't look too bad.

The wear patch is a different width on them.---:}

Is one brush wider than the other ???

[Bolin]

Measuring the photo the wear is a tiny bit wider on the left, using a ruler against my screen it is 26mm on the left and 25mm on the right. But on the left it is shallower.

The brushes looked the same width.

There is some pitting but it looks OK.

I need to measure the output, I couldn't find a guide for this in RAVE or Haynes. I've done it on another car. Time to dig out the old Haynes Electrical Manual.

[Bolin]

Slip rings photo has gone again - rah!

I think my next move will be to check for 12v at C0226-1.

I am assuming the slip rings and brushes are OK.

If no 12v - check every point back from there.

If there is 12v - voltage regulator failed?

[Mike Noc]

Yes the brushes and slip rings look OK to me.

If you want to borrow a good known alternator I'm sure I've got one laying around somewhere in the garage.

[Bolin]

Thank you for the offer Mike.

If the alternator itself is faulty, then I guess it must either be the voltage regulator or the windings have somehow broken down? Is that even possible?

I'll order a new voltage regulator if there is 12v going in and the cable to the starter motor and on to the battery is OK.

[klarzy]

There is a fuse on the excited circuit..

[Bolin]

Right I removed the connector plug and turned the ignition on - no warning lamp, as I expected.

I then measured the two pins in the plugs to earth, one was 11.4v, the other 10.somethingv.

I traced the cable to the starter motor and battery, no loose connections.

Klarzy - which fuse? car runs and drives OK. I can't see another fuse which would allow car to work but not the alternator.

I think the best option is to buy a replacement alternator at tis point - after some reading it doesn't look like regulator failure. And I need the car on the road ASAP.

Mike - thanks for the offer to try a known working alternator - problem is I can't trust the car to get me to Bordon and back (from Fleet) and I don't fancy doing too much swapping of alternators, it looks a right nightmare in RAVE. :(

Just hope with a fully charged battery I can do a trip of 1 mile each way tomorrow (two starts).

[Mike Noc]

With a good fully charged battery you can do a fair few miles Colin. I once drove over 40 miles when my alternator failed, including a few starts (to get on and off the ferry - it failed in France).

If you have a spare battery also worth packing that, just in case.

[Bolin]

Ah that's great, many thanks for that info - it puts my mind at rest as I need to take my Dad for jabs at the GP surgery tomorrow, less than a mile there and back, and was very worried that the car might not start for the return journey. The battery is a Varta E44, the best available I think, and is currently charging.

I do have a spare battery but it appeared to have failed, it is smaller than the other, perhaps the alternator was on the way out and the battery is OK. Will investigate.

I have already ordered a replacement (2nd hand alternator), should arrive mon/tue. So maybe I can do a return trip of 6 miles each way on Sunday as planned.

Thanks again for the offer, but I already ordered the replacement alternator earlier today before I read your post, so probably makes most sense to fit that and then do a post-mortem on the old one, so I just swap the unit once. It looks a bit of a fight, but I think I saw a how-to here so hopefully that gives an easier option.

[rustymotor]

Hi, given the cost of a new alternator I paid £110 for mine and the work involved is it not false economy to fit a used unit?