Alternator issue ?

Good to know that there are good independent engineering firms in the south west too!

If anyone in the West Midlands is looking for a similar service, I can recommend C J F Rotating Auto Electrics Ltd in Hednesford, Staffordshire. I dropped in with the starter motor off my canal boat at 4pm & told them there was no urgency - they called me at 12.30 the following day to say it was ready to collect. It looked as new & the old Lister twin fired up first turn of the key.

Nice job done there Paul ........ just make sure that you fit a NEW suppressor to the alternator, a new one will not be the same size .... it will be smaller, but you will need one so you don't get the alternator whine and possible ign interferrence on your newly overhauled radio.
BTW ... in the pic below, the old one was not wired in correctly, you will notice it is just shorting itself out on the negative connection.

PS Just checking this post on preview, I notice that the nut holding the suppressor does not seem to have been undone ..... but the nut just below the Positive terminal has been ........ tell me, was the earth wire from the loom connected to that nut below the positive terminal and not the alternator's negative terminal that the suppressor is bolted to ?

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Hi John,

The photos of the existing unit were taken just after I removed it from the car. The suppressor black lead was connected to the negative terminal and the red lead went to the positive nut – which sheared off.
The small spade connector on the black lead to the negative terminal also fell apart.
Why do you say the suppressor was not fitted correctly, as the black lead went to the negative and the red lead attached to the positive post.

I was going to simply fit the original suppresser as it appeared to still do its job .

Why do you say the suppressor was not fitted correctly, as the black lead went to the negative and the red lead attached to the positive post.

My mistake Paul ...... not seeing a red lead on the suppressor, I assumed it was a single wire with the earth connection through the suppressor case, as most of them are these days with a black lead going to the positive stud.
Just looking at the condition of the suppressor case, I would be inclined to replace it anyway. If you do intend to reuse the old one, it might be worth checking its capacity and leakage ..... if it is in anyway suspect, one of these should do the trick.

http://www.ebay.co.uk/itm/Car-Radio-Noi ... Sw9r1V-pnY

So, after an hour of huffing and puffing I managed to get the new alternator on the car.
Started her up and the battery voltage rises to 13.24 but doesn't increase any further if I rev the engine.

The battery is brand new fitted 4 weeks ago. So my question is, if the battery is fully charged, then would you expect to see a higher voltage or does the regulator simply stop charging until it falls below a threshold?

I've checked the positive connectors behind the rear wheel and cleaned up the earth immediately below the battery. I recall there is another earth on the engine, but I cant locate this.

I did notice the plastic connector that fits onto the alternator regulator was a bit crappy, so I sprayed switch cleaner in the connector .

You need to put load on to see voltage increase .Switch on lights,blower etc and you should see a rise

You need to put load on to see voltage increase

I did that and the voltage dropped to 12.8

I've since connected my volt meter across the positive terminal just behind the rear wheel and chassis. Saw a reading of just over 14 volts. So I then ran a long piece of lead from the positive battery terminal and checked the volt drop between this and the positive terminal behind the rear wheel; it was negligible. So this confirms I'm not losing voltage in the positive feed.

So, I then checked voltage across the battery positive and the chassis and this is only 11 volts.
Must be a bad earth, I cleaned up the battery negative earth but where are the other earths?
I see one earth strap from the gearbox and I know of one in the driver's footwell RHS. Are there any others that would have a direct affect on the charging side ?
Sounds like it may have been a bad earth all along, as it sometimes hesitates to crank over.

There is one on the gearbox, another on the Rhs rocker cover.
I attached another from rear lhs turret to lhs rocker too and at the front added another to the lhs strut tower.
Did the trick.

Dave

Looking at the green on your old alternator pins, that's where I'd be looking, are you sure the switch cleaner has taken all the gunk off the two pin plug, an acidic alloy wheel cleaner will strip them right back to bright metal then you can wash with a little water and WD40 and Vaseline them.
If you do acid wash them, make sure you get it all off and protect it as above.
With my voltmeter fitted in the car on an ignition switched live I now get a max of 14.5V driving (1500 rpm +) and it never goes above that, adding lights drops it to 14.2V , blower however is the biggest draw, dropping it to 13.8V.
At idle it is about 13.5 - 13.8V.

I've checked these readings against my multimeter and they are accurate enough.
Battery is about a year old and reads 12.6V at rest, 13V+ after a run.
Voltmeter in the car might seem a bit OTT, but I had big charging issues with one of the old japanese bikes so went into it a bit gaining a fair bit of know how on what should be what, thanks to a Suzuki GS forum, and dirty connections was the root of all evil, killing otherwise serviceable components.
I only have the original battery to crossmember earth and also only the gearbox to chassis earth, never in my ownership has it had the rocker box earth, but extra earths can only help so if everything else, including the original earths are bright and shiny then its the way I would go, especially if you get slow cranking sometimes.
Good luck.

Many thanks Turbell. Yes the regulator connector look a little worse for wear when I prised it off the old alternator. I thought then if a spray of switch cleaner was going to do the job.

This afternoon I checked the gearbox to chassis earth which seems good. I then decided to remove the earth strap from battery negative to chassis. Spent 20 mins cleaning the strap and body. That seems to have helped on the starting front; cranks over more easily. But the battery voltage stayed the same around 13 V. I then fiddled about with the regulator connector. I was intending to remove it, but I cannot without taking the positive connector off which in turn means taking the alternator off - or at least dropping it down for access etc.. So I started wiggling the connector and hey presto 14 volts appeared !!

I'll wait for another fine day and remove the connector to try clean it more thoroughly.

Great news, looks like you're on the right track, you'll have a tip top charging system, a reliability must have!