Ignition light staying on

[Napoleon Boot]

Hi all,

I've read through other threads and tried to troubleshoot this, but no luck so thought I should consult the group!
As the subject line says, the ignition light on the speedo isn't going out no matter how long I drive for. It's not massively bright - the light gets dimmer and flickers once the engine is running, but it doesn't go out altogether.

I've checked the connections to the alternator and to the distributor, everything appears to be correct and tightly connected. I thought it might be that the battery was not accepting a charge, as it was on its last legs, but I've fitted a brand new battery and the situation is the same. I've checked that the fanbelt is tight, and I can see the alternator is whizzing around as it should when the engine is running.

I recently fitted an Accuspark electronic ignition kit, and I'm wondering whether this may have caused the problem, as I don't recall seeing the ignition light stay on before. The kit worked first time when I installed it, and it's only a matter of connecting two wires so I'm not sure what effect it could have had...

Seb

[simmitc]

Noted that you have an alternator. You are describing classic signs of an alternator that needs attention. If you feel competent, then DIY repair is possible, if not, then just slap in a new one. The accuspark will not have caused the problem.

[Napoleon Boot]

Noted that you have an alternator. You are describing classic signs of an alternator that needs attention. If you feel competent, then DIY repair is possible, if not, then just slap in a new one. The accuspark will not have caused the problem.

A ha, I thought it might be the alternator based on other threads, but was hoping against hope that it might be something as simple as a misplaced wire. I will have a look for a thread about troubleshooting alternators in that case - I'm not bad with a multimeter now so it might be something I can do myself.

[pgp001]

Just have a double check that the small ignition light wire is fully connected.
It is really easy to disturb that wire if you have been doing some work on that side of the engine.

Also, before you buy a new alternator, check the voltage across the battery terminals with the engine stopped and then with it running.
If you are getting a charge it should go up to just a tad over 14 volts.

Phil

[Napoleon Boot]

Just have a double check that the small ignition light wire is fully connected.
It is really easy to disturb that wire if you have been doing some work on that side of the engine.

Also, before you buy a new alternator, check the voltage across the battery terminals with the engine stopped and then with it running.
If you are getting a charge it should go up to just a tad over 14 volts.

Phil

Thanks Phil; the ignition light wire seems to be connected fully but I will double check, it seems more likely that I disturbed it than the alternator just conking out. I'll check the battery with a voltmeter and see if there's any change with the engine running, if not I guess I'll order a new alternator from ESM as there doesn't seem to be anything easily repairable, from what I've read.

Seb

[geoberni]

if not I guess I'll order a new alternator from ESM as there doesn't seem to be anything easily repairable, from what I've read.

Seb

Depends on your level of knowledge and confidence with such things. Take a look at youtube and there's plenty of instructional videos.
For example this one: https://www.youtube.com/watch?time_cont ... e=emb_logo

There's not much to an alternator. If it sounds OK, then the bearings are probably fine, so it could be the brushes or a simple connection break. The link above is good for showing a break at the diode pack and how it can be replaced quite cheaply.

[Napoleon Boot]

[/quote] Depends on your level of knowledge and confidence with such things. Take a look at youtube and there's plenty of instructional videos.
For example this one: https://www.youtube.com/watch?time_cont ... e=emb_logo [/quote]


Thanks for the link, I hadn't found that video so I'll give it a good watch.
I've been out with the multimeter; the ignition light wire is firmly connected and the fanbelt isn't slipping so I think it is something inside the alternator that's gone wrong. With the engine off, I'm reading 12.44 volts which drops to 12.27 with the engine running at 2000 revs and radio and sidelights on. I wanted to check the voltage with the main beams on full, except the fuse has blown! As I've not been out in the dark for a while I don't know if this has just happened, but I suspect it has. Agh!
With the engine switched off the voltage reads 12.44 again.

I'll watch the video now and see whether I think a rebuild is within my abilities - won't be going anywhere anytime soon so it's not really urgent...

Seb

[simmitc]

The headlamps are not fused on a standard car. If you have a blown fuse, which one, and what else isn't working? The headlamps not working is probably a wiring issue.

[oliver90owner]

If it is glowing dimly, it is likely a rectifier fault. There are web sites that list different alternator faults. If rectifier, the the charging voltage will be insufficient but it may be charging ‘a bit’.

If the lamp is glowing normally some or most of the time it is more likely the brushes - the outer one (nearly) always wears faster than the central one 9I usually only change one brush.

There is the possibility that the commutator requires cleaning up or replacing.

These parts are all fairly easy to change and far cheaper than an exchange unit that may, or may not, have been fully refurbished with unnecessary parts. I’ve only bought one exchange alternator in the last 40 years - it included the power steering pump as well - and even that turned out later to be a wiring problem from a “bump” before I owned the car.

[Napoleon Boot]

The headlamps are not fused on a standard car. If you have a blown fuse, which one, and what else isn't working? The headlamps not working is probably a wiring issue.

Actually the headlights are a red herring; I remembered that I had to fiddle around with the indicator/wiper stalks (not standard) in order to refit a dashboard trim panel, and I was too lazy to disconnect the battery and shorted a couple of wires while I was at it. Whoops

If it is glowing dimly, it is likely a rectifier fault. There are web sites that list different alternator faults. If rectifier, the the charging voltage will be insufficient but it may be charging ‘a bit’.

I'm afraid I took the coward's way out and ordered a new alternator from ESM; I'll have a good look at the old alternator once I've swapped them over though, as I don't like throwing things away, plus I'll take any excuse to take things to bits and see what's inside.

[oliver90owner]

I expect it is brushes. It usually is. A fiver for a set (at most?) and like as not you would only need one of the pair.. The centre brush will still likely have a huge service life left.

No need to remove the alternator from the car (in this instance) to replace. Remove electrical connector(s), remove rear cover, remove screw holding brush in place and remove brush. Reverse the procedure to install new brush.

If brushes wear quickly the slip ring may need cleaning up with abrasives, or if badly worn it may need replacing (a simple soldering job). Regulators rarely give trouble and are a simple replacement job (probably two screws and spade electrical connection). Rectifiers do fail (not often these days) and are a simple replacement job. Brushes likely only transmit a couple of amps, so are not exactly heavy duty items (like brushes in a dynamo).

Reverse battery connection will kill the diodes, as may electric welding without disconnection of the alternator. Diodes do not like to be subjected to high voltages or excessive current and once subjected to either become moribund in milliseconds or less!

Drive end bearing lasts a long time but is usually damaged by over-tightening the drive belt. Cheap as chips from my local bearing supplier. Serpentine or poly V drive belts are used on modern vehicles and that generally removes the problem of owners over-tightening worn out V belts instead of replacing same.

I think I have only ever changed one bearing at the slip ring end as they are not a stressed item. I think I likely changed it as a matter of course when installing a new slip ring on a ‘high mileage’ unit.

That leaves the rotating field shaft (basically a electromagnet on a steel shaft) and the stator which are very reliable. They generally only need changing if damaged - that is time for an exchange replacement?

Generally, alternator failure involves only one faulty part.

[Napoleon Boot]

I expect it is brushes. It usually is.

You're absolutely right! I took the old alternator off and opened it up; one of the brushes had come away from its spring/wiring and was lying loose in the bottom of the brush box:

IMG_7906.jpg (1.47 MiB) Viewed 2204 times

It had been rubbing considerably on the slip ring; I have cleaned it up with meths and with some Servisol, but the slip ring is still very scored; is this likely to be a problem?

IMG_7908.jpg (1.93 MiB) Viewed 2204 times

Now, I have a quandary. I ordered a replacement alternator which arrived today; my plan was to fit it and then fix the old one at my leisure and sell it on. There's a problem though - although identical in all other respects, the mounting lugs of the new alternator are spaced 5mm further apart than the old one. The old alternator was kept in place with a nicely machined spacer (painted green in the photo below), which is now 5mm too long.

IMG_7900.jpg (2.41 MiB) Viewed 2204 times

As I don't have a workshop, I don't reckon my chances at cutting off the excess accurately or making a square cut. I could order a length of threaded rod and fasten with nuts and washers either side of engine brackets, as that's what it looks like others have done.

Alternatively, I could take the brushes (and slip ring?) from the new alternator and fit them to the old, a multimeter test shows that the diodes are OK. Do you think the slip ring will need replacing though?

Thanks in advance,
Seb

[geoberni]

Well, we did recommend having a look first.....

Now you've got another problem(to some extent of your own making); .... the last thing I would do however is go playing 'mix and match' with parts from a perfectly good brand new item you've just brought that is presumably under warranty!
You might ruin something else and end up with 2 duff alternators!

Is it really going to be beyond your capabilities/resources to cut 5mm off the green tube with a hacksaw?
Mark a line all the way around the end of the spacer at the required distance and cut slowly a couple of strokes at a time....

It had been rubbing considerably on the slip ring; I have cleaned it up with meths and with some Servisol, but the slip ring is still very scored; is this likely to be a problem?

Cleaning it with liquid isn't going to remove scratches.... try some fine grade Wet n'Dry paper on a flat surface, taking care to keep it square. Above all do it slowly and only take off the minimum to level it a bit.

The headlamps are not fused on a standard car. If you have a blown fuse, which one, and what else isn't working? The headlamps not working is probably a wiring issue.

Actually the headlights are a red herring; I remembered that I had to fiddle around with the indicator/wiper stalks (not standard) in order to refit a dashboard trim panel, and I was too lazy to disconnect the battery and shorted a couple of wires while I was at it. Whoops

So we established that there is no fuse for the headlamps and that you shorted some wires whilst 'fiddling'... so what happened next?
Have you left some disconnected wiring somewhere?
Did you actually short them enough to burn something out?

[Napoleon Boot]

Well, we did recommend having a look first.....

Yes, I know...

So we established that there is no fuse for the headlamps and that you shorted some wires whilst 'fiddling'... so what happened next?
Have you left some disconnected wiring somewhere?
Did you actually short them enough to burn something out?

No, there is a fusebox fitted on the car by the previous owner, as he fitted heated windscreen/rear window and various other non-standard bits that need fuses. I shorted the wire from the headlight stalk while refitting the driver's side glovebox trim; replaced the fuse and it's all fixed now. I hadn't disconnected the battery as I wasn't working on anything electrical, but of course the headlight switch is always live and the dashboard is part of the car's body which is the ground, lesson learnt.

[oliver90owner]

It only fell out as you took it apart, but fairly clearly that was your problem.

That slip ring definitely could do with flatting - as good as the ‘un-rubbed’ bits. Easy enough if you have a wide range of abrasive sheets, but not much cheaper (if you need to source the abrasives) than unsoldering the slip ring and fitting a new one.. Relatively ‘cheap as chips’ compared to an exchange alternator. Check the bearing while at it, too. If that one requires changing, the front one also likely needs changing.

I note that the slip ring appears to have worn off-centre , possibly increasing wear. That might indicate further wear in the unit (possibly bearings) which needs to be investigated. Or it may just be a cheap slip ring.

The usual finding is the outside brush being below service limits while the central brush is almost ‘as new’.

Re the ‘length issue’ - I doubt it. They are made with a sliding ferrule in the ‘free end’. Which means the alternator is fixed tight at the pulley end (so the belt is automatically aligned) and the other securing bolt tightens as the ferule slides within the bracket. Check it out.. Your belt does not look as though it is straight - check with a straight edge - if it does not touch both sides of both drive and driven pulleys, it is mis-aligned.

It looks to me that that conversion from dynamo has been bodged, as those washers at the front end should not really be needed. I may be wrong, but do check it out.

RAB

Edited - don’t cut that spacer with a hacksaw- unless you are good at it. Better to turn it down in a lathe to avoid any stresses due to mis-alignment. Normally there are two bolts with an alternator one fixed and the other floating.

[Napoleon Boot]

That slip ring definitely could do with flatting - as good as the ‘un-rubbed’ bits. Easy enough if you have a wide range of abrasive sheets, but not much cheaper (if you need to source the abrasives) than unsoldering the slip ring and fitting a new one.. Relatively ‘cheap as chips’ compared to an exchange alternator. Check the bearing while at it, too. If that one requires changing, the front one also likely needs changing.

Many thanks; I've got multiple grades of abrasive paper so I can easily flat it back, if I can't get a good result I now have a spare slip ring at least!
Actually, given my experience with the car so far, once I've fixed one thing another bit will probably break, so I'm glad I have a spare rectifier to hand as well.

Re the ‘length issue’ - I doubt it. They are made with a sliding ferrule in the ‘free end’. Which means the alternator is fixed tight at the pulley end (so the belt is automatically aligned) and the other securing bolt tightens as the ferule slides within the bracket. Check it out..

Is this the sliding ferrule?

IMG_7911.jpg (524.6 KiB) Viewed 2177 times

If so, there's still not enough room to get the green spacer in - I think, like much of the car, this was a piece the previous owner made from scratch- the ferrule fits into a rebate cut into one end of the spacer and the remainder goes through the lug in the alternator. Not that this is a problem now I'm using the old alternator which has the lugs 5mm closer together (I checked with calipers).

Your belt does not look as though it is straight - check with a straight edge - if it does not touch both sides of both drive and driven pulleys, it is mis-aligned.

I think it may be an optical illusion in my photo - I checked and the pulleys line up (though they wouldn't without those spacers). It probably is a bit of a bodge, I think the previous owner made the parts to fit rather than using an off the shelf conversion kit.

Anyway, I swapped the whole brush box and regulator across from the new alternator to the old, fitted it and it works perfectly, the ignition light is going out straight away and the battery voltage is over 14v with the engine running so problem solved. I couldn't fit the new alternator as the bottom bolt was also too big for the threaded hole on the bottom bracket already on the car. The way I look at it is that I've fixed the fault, learnt a bit about alternators and have a few spares in hand. I will flat the slip ring though, and check if the wear is even - I think it is, it looks it in real life but looks different in the photo due to the light. If not I have spare bearings to use.
Thanks all for your help!
Seb

[oliver90owner]

The copper of the slip ring has a finite thickness. When it is gone it is new slip ring time

That ferrule/bush is the one I was referring to. With two bolts (instead of the original long bolt for the dynamo) the front bolt fixes the position of the pulley and the rear bolt would tighten up pulling the ferrule into whatever position it finishes with the bolt tight. The long spacer you have at the rear of the alternator correctly fills the space, but there should be a long and short bolt.

I was thinking the track, made by the old brushes, was wider than the brushes - hence needing investigation.

Good that you have fixed the problem - even if not completely. Alternators can last a long time and only usually require cheap fixes. Mine and my wife’s last five vehicles were/are high mileage and I would think each vehicle was likely on its first alternator (248k, 195k, 169k, 170k and 129k - they may have been changed, I suppose but our total mileage has been 220k with those vehicles and I haven’t needed to do anything more than change one belt and adjust the belt tension once). Not bad as none of them have been younger than 12 years at purchase and my current run-around (129k) is 24 years old next month.

As an aside, the three were changed due to accident damage, blown turbo and clutch change - each one simply needing non-economic repairs

[simmitc]

Looking at your photo, it appears that the original mounting bracket for the rear of the dyanmo has been used. There is a different bracket available for fitting an alternator, and this will bring the bracket next to the edge of the alternator. This would allow you to use a short bolt at each end of the alternator, and ensure ocrrect mounting. At present, it looks as though there is a long bolt plus your spacer. This means that when tightened, the brackets on the alternator casing will be in compression and this could risk a fracture.

The correct brackets are readily available and easy to fit. I recommend upgrading to the correct solution which should provide a good long term solution and not require any machining.

[StillGotMy1stCar]

As above, this bracket also includes the correct adjuster.
https://www.ebay.co.uk/itm/Classic-Mini ... 0033.m2042

Regards John