What Did You Do Today (2016)

[JAParticipant @ja]

Thank you all for the advise on python. I am aware that there are differences between versions 2 and 3 and have tried both with the same result. I have joined the python forum and posted my problem. I will wait and see what happens.

JA

[Neil WyattModerator @neilwyatt]

Pulled onto the A38 this morning, after about half a mile, battery light flashed on, then went off. Slipping belt?

Then found myself on the end of an 8-mile queue moving at sub-walking pace/

A mile or two further, light came on. Then speedo and tacho died. Then each system on the car started dying in turn… tried turning things off but the heater and heated seats wouldn't switch off! Gradually everything dies except engine – pull over rather than wait for inevitable.

After half-hour in queue, my wife collects my daughter, but another 40 minutes for the AA to get through, swap in a full battery and get home with everything switched off after another 20 minutes in the queue, alternator light on all the time now. Time for a new alternator, and suspicion on battery given how fast it died.

B***r

[BazyleParticipant @bazyle]

Sounds like the regulator. Used to be a few quid and DIY but now probably can't change it as a part and have to chuck the whole engine.

[john swift 1Participant @johnswift1]

 

must of been in the 1970's the Lucas alternator on my dads Vauxhall viva stopped charging

the ignition light went out when the engine was started but came back on soon after

luckily the thick film regulator was encapsulated in silicon rubber that made it easy to remove and test the various components

half an hour later , after replacing a faulty transistor with a ZTX107 the alternator worked on the bench

had to wait for a tube of electronic grade silicon sealant to arrive from Radio Spares (RS Components) – not the common DIY sealant that gives off acidic fumes !

the last time I checked an alternator (Bosh) the regulator was combined with the brush holder – easy to replace

not sure how cost effective

 

John

PS if I remember correctly it was Q1 that I replaced

 

 

 

 

 

 

 

 

 

 

Edited By john swift 1 on 20/01/2016 15:00:53

[Neil WyattModerator @neilwyatt]

Posted by Bazyle on 20/01/2016 13:22:37:

Sounds like the regulator. Used to be a few quid and DIY but now probably can't change it as a part and have to chuck the whole engine.

The AA chap reckoned that with this alternator you can pull off a certain connection (possibly the sense connection?) and if its the regulator gone it will then output a straight 14.4V. He did and it didn't

Neil

[MuzzerParticipant @muzzer]

Haha. If it regulated at 14.4V magically without a regulator, why would they bother fitting them?

"the last time I checked an alternator (Bosh) the regulator was combined with the brush holder – easy to replace not sure how cost effective" – you can design everything to be easily serviceable but the Japanese lesson was that it's cheaper overall (total cost of ownership etc) to design it so it doesn't fail in the first place. It's arguable that the brushes are serviceable items, so at least this approach doesn't require the whole alternator to be scrapped.

[Clive HartlandParticipant @clivehartland94829]

I thought the alternator gave out AC and it was turned to DC at about 14.5 V, alternators give volts at low speeds.

What i have found is that the brushes wear and skip and cause output problems, replacement is quite simple. Also brush dust can cause problems.

As an aside Yachts trail a propellor on a cable attached to an alternator in a bucket and sealed watertight to give battery charge while sailing, but fish take the prop thinking its bait. I know a sailor who lost at least 3 on an Atlantic trip.

[V8EngParticipant @v8eng]

The Lucas Car Alternators had radial slip rings, one common cause of failure on higher mileage cars was the outer brush wearing much more than the centrally located one. That also tended to cause an uneven wear pattern on the slip rings.

The rotor could be removed and the slip rings skimmed in a lathe, we only ever risked doing that to any particular alternator once.

Generally speaking the Alternators were pretty reliable and better than dynamos at keeping keeping the ever increasing electrical loads going.

Edited By V8Eng on 20/01/2016 17:17:45

[clogsParticipant @clogs]

Neil, get a quality rebuilt unit…..

.with down time and all the trouble finding parts not worth the effort and remember the brushes, bearing etc will be on their way out as well…..

be careful there is a lot of rebuilt units from Serbia, Romania etc on flee bay …..

there are quality UK rebuilt units out there, they are just not the cheapest……

clogs

[Anonymous]

Posted by Clive Hartland on 20/01/2016 17:15:54:

I thought the alternator gave out AC and it was turned to DC at about 14.5 V, alternators give volts at low speeds.

It does there is a rectifier that converts it to DC then a regulator to give the correct DC voltage usually all built into the alternator. Lot easier on most motor cycles which have a stator and seperate reg/rec unit that lets you troubleshoot a lot easier.

[Neil WyattModerator @neilwyatt]

I want a quick get-going solution. I may just swap the brush box over, and if that's the fault I might recon the old one because with 4 of the same car in the family it won't be long before another is needed .

Neil

[Alex CollinsParticipant @alexcollins55045]

Walk into a car spares place and get a service exchange. That way you know you hav​e an as good as new alternator.

[jason udallParticipant @jasonudall57142]

Swapping out the alternator often fixes the problem..
Sometimes not for the expected reason.
To change the alternator you will remove the battery leads…at battery
You unplug/unbolt power and “ign” wires

You un bolt the sad thing
Now the surprise.
You clean the earth connection before fitting the changed unit..you check /set the alternator belt
You clean and reconnect the wires. …
And test

Hussah ! the new alternator works…

Now was it the alternator or was it the clean /refit of the connectors? ….

Edited By jason udall on 20/01/2016 18:47:50

[Neil WyattModerator @neilwyatt]

Posted by Muzzer on 20/01/2016 16:10:36:

Haha. If it regulated at 14.4V magically without a regulator, why would they bother fitting them?

"the last time I checked an alternator (Bosh) the regulator was combined with the brush holder – easy to replace not sure how cost effective" – you can design everything to be easily serviceable but the Japanese lesson was that it's cheaper overall (total cost of ownership etc) to design it so it doesn't fail in the first place. It's arguable that the brushes are serviceable items, so at least this approach doesn't require the whole alternator to be scrapped.

I think he wasn't meaning exactly 14.4V, rather that the flat battery's voltage starts rising towards it if the regulator is disabled.

Plus no profit in alternators that don't fail…

Jason – he disconnected and reconnected everything, including the battery.

Neil

Edited By Neil Wyatt on 20/01/2016 19:45:26

[frank brownParticipant @frankbrown22225]

JohnSwift 1, its a shame they did not put a 100 ohm resistor inside the unit between the sense and the output wires, if the sense wire becomes detached the charge goes to max and boils the battery. If Q3 goes short circuit, the voltage rises and blows every bulb in the car and the computer. . . ..

Frank

[john swift 1Participant @johnswift1]

I understand they made 2 versions of the alternator

one with the sense wire measuring the voltage at the positive battery terminal and another internally linked to the alternator positive output

if the sense wire is disconnected you have no positive supply to R4 which supplies the bias to switch on transistors Q2 and Q3

I guess if Q3 goes short circuit , the alternator will be so hard to turn at speed the belt will start to slip and screech

unless your answer to any  new noise is to turn up the radio a bit louder

you should find the fault before the battery is boiled dry

 

John

 

 

Edited By john swift 1 on 20/01/2016 20:26:51

[Ian PParticipant @ianp]

Posted by Neil Wyatt on 20/01/2016 19:44:22:

Plus no profit in alternators that don't fail…

Neil

My understanding is that the OEM (of the car and its components) want to make their main business selling complete cars. The longer the components last the more likely the company will get a good reputation and sell more cars. Supplying spare parts is not their main aim, in fact I imagine they would prefer not to stock and distribute spares at all.

The high cost of original spares is partly because the parts are so reliable. Of course everything gets skewed once 'pattern' parts are taken into account. The makers and sellers of aftermarket spares are not too concerned about the life of their products.

Like a lot of people here I hate waste and avoid throwing things away in case they come in useful (they frequently do) but I can now see some sense in cars having a pre-defined lifetime and once a car starts to have multiple failures the whole thing is scrapped and recycled. Cars are now getting increasingly complex that I can see the electronics and software will fail before the mechanical parts have worn out.

One area of engine manufacture that I have heard of recently is cylinder heads that are totally unrepairable, if a fault develops the whole head is replaced! Camshafts are assembled inside the actual head casting and the valves etc cannot be removed. To someone (me) who grew up with regular 'decokes' and engine rebuilds a 'cassette' cylider head made no sense at all but most car engines now never have any work done to them in the life of the car. I would imagine the cost of a cassette head will be much cheaper than the labour and spare parts required to recondition a standard head.

Ian P

[Speedy Builder5Participant @speedybuilder5]

I was at the local garage today and saw a Mercedes in for a repair – the alternator has water connections to the cooling circuit !!

[Allan WainParticipant @allanwain40936]

Hi all,

Modern alternators are far removed from the alternators of old. Most are now "smart charge" where the alternator is ECU controlled, it switches off to remove load when cranking, charges hard when on over-run or braking ( sometimes up to 18 volts) and varies current generated based on a number of parameters. The disconnecting of one particular wire removes "smart" control & makes the alternator work like an old fashioned one ( but not on all smart charge systems), this is a communication wire to the ECU with a two way communication transferring demand & feedback information.

[Ian S CParticipant @iansc]

I'v been doing a little work of late on a Chamberlin tractor (Australian made), with a 6 cylinder Perkins engine, the alternator is switched by the oil pressure. The switch leaks oil behind the instrument panel, so that system is coming out, and a conventional system will be used.

Ian S C

[michael howarth 1Participant @michaelhowarth1]

Bought 300ml Baufix Graphite Oil spray from Lidl for £1.99. I have always been impressed by Baufix products.

Mick

[Neil WyattModerator @neilwyatt]

I'm waiting on Lidl rust-remover spray so I can get the last nut off my old alternator. Bad attack of Dumpy's Ruisty Nuts.

What an 'orrible job, had to drop the engine off its end mount just to get a bar in to loosen the tensioner. what was wrong with the old technique of tensioning a breaker bar behind the alternator!

Neil

[BazyleParticipant @bazyle]

Rust remover spray? Just use 2 stroke fuel from the strimmer. Rust remover is just paraffin and oil anyway with a dash of patented hokum thrown in.

[DodParticipant @dod]

We can't get it back in

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, in the eight or so years that I've had my Astra, I've had to replace my alternator twice. The first time I had to replace it, I did seek to find a replacement regulator, but only found one supplier, that was all very well and it would have been cheaper than a new alternator, the down side was that it only carried a warranty if they fitted it and there was no guarantee that there was no other fault with the alternator. A recon one was the cheapest way to go and buying two recons was still cheaper than buying a brand new one. Seems on this particular model, the regulator is integral with the rectifier.

Regards Nick.

[Author]

Posts