rlubikey Posted May 10, 2017 Report Share Posted May 10, 2017 Sorry not to have made the Shire Horse yesterday evening everyone; my alternator had packed up. The battery was dead and must have been dying as I drove back from the SEM on Saturday. Jump starting worked, but the Ign. light didn't extinguish. Quick check and I've got 11.5V and barely charging when I rev a little. Switch the lights on and deffo. *not* charging. Waggling the connector doesn't help. Out with the alternator! So, on my bench today and it's obvious that two of the three "exciter coil" diodes had expired - these are the little ones that are visible on the top of the rectifier pack. They had cracked (never a good sign, as it's evidence the smoke has escaped!) and one had been hot enough for the solder to melt. Fortunately they are a common type that I just happened to have to hand - 1N4003 (it's handy being an electronics engineer!) - so in they go. The big diodes checked out OK so this evening I put the alternator back in the Spit and all seems well. So, why do these things spontaneously combust? Last time I changed the rectifier pack (2012, I think) I searched for some NOS and this one came in a MoD sealed packet. Quality, I thought - got to be better than the recon. alternator that failed in no time back in 2005. Perhaps not. Maybe it's time to go for one of those little Nippon-Denso ones. That's it - rant over! Cheers, Richard Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 10, 2017 Report Share Posted May 10, 2017 we had a reconditioner supplying recons for trucks and if the diode had failed they just cut its wire ,, puts the glowing lamp out ,but lowers charge capacity nice box though , quite a nightmare . Pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted May 11, 2017 Report Share Posted May 11, 2017 5 of us at East Berks Tuesday, not much to report, Mark has had an alarming haircut. Gave us all a laugh. My GT6 packed up Tuesday afternoon, no spark! Hope it's not the Aldon electronics, the spare part I sent to the USA for has only done 50 miles. Fitting points and condenser today to check it out. Might be the coil, but I've never had one fail on any car I've had. Mark said "It's about time you did then!" He's a caring sole! New Aldon is £150! John's recently fitted a PowerSpark which he enthused about, only £35. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 11, 2017 Report Share Posted May 11, 2017 best of luck let us know ....will this affect your vote the news is getting yawn !! Pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted May 11, 2017 Report Share Posted May 11, 2017 There's an election, apparently. Mrs May is my MP, is see her in Waitrose occasionally. Odd to see her on the box when the day before I've stood next to her discussing the merits of "Aunt Bessies". OK points and condenser installed. I have spark at points but not at plug. Has to be the coil? It must have got pretty hot when the head gasket blew and they don't like it up 'em so, a shiny new coil. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 11, 2017 Report Share Posted May 11, 2017 Its a classic when you cure the fault it doesnt cure the problem Ha!! pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted May 14, 2017 Report Share Posted May 14, 2017 It was the coil! Replacement fixed it. Took longer than expected because I lost the rotating electronic ignition magnet. Couldn't find it, I figured it must have fallen into the engine bay and being a magnet got stuck to something. I had just about given up, resigned myself to putting the points back when I reached up to close the bonnet and there it was stuck to the air intake grill. I had closed the bonnet during a previous downpour and that's how it happened. Doh! Perhaps I should put this on the dinosaur thread. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 14, 2017 Report Share Posted May 14, 2017 Most Dinosaurus lays eggs but never had a magnet unless you know something else Link to comment Share on other sites More sharing options...
rlubikey Posted October 10, 2018 Author Report Share Posted October 10, 2018 So, last night on my way to the Shire Horse I had to turn back when I saw the Spit's ignition light glowing. Checking battery volts at home and it's obvious the alternator isn't charging. This is a new alternator - one of those 60A jobs from that well respected Triumph vendor near Coventry. What is it with me and alternators? It's only 15 months old! I'll yank it out this evening and see if it's an easy fix. If not then various East Berks members have suggested Burghfield Starter & Alternator Centre so I'll give them a go. Cheers, Richard PS: Some people seem to modify the thread title when replying. How do you do that? Link to comment Share on other sites More sharing options...
dougbgt6 Posted October 10, 2018 Report Share Posted October 10, 2018 Richard, Should have said last night but it's easy to replace the diode pack, regulator and brushes, Burghfield S & A may not be needed. Just a screwdriver and a soldering iron required. https://www.ebay.co.uk/itm/Alternator-Repair-Kit-Rectifier-Regulator-Brushes-Fits-LUCAS-15-16-17-18-ACR/201669312542?hash=item2ef46d801e:g:UkYAAOSw8w1X2TOz To modify title just press edit, do what you want and save Doug Link to comment Share on other sites More sharing options...
NonMember Posted October 10, 2018 Report Share Posted October 10, 2018 I fitted one of those kits to a dead alternator I had lying around and fitted it to my Spitfire. Works great, although for various non-electrical reasons it hasn't covered many miles yet. It's an easy job and definitely worth a go. Link to comment Share on other sites More sharing options...
rlubikey Posted October 10, 2018 Author Report Share Posted October 10, 2018 Hi Guys. Yes, the alternator came out tonight and the diode pack has two visibly faulty rectifiers. I've replaced the diode pack and the regulator on various alternators before. I'm a dab hand with a soldering iron, if I say so myself, so that doesn't put me off. It's the quality of the replacement parts you buy which really does seem like a lottery. My worry is also that it may be (a) faulty winding(s) and that I'm throwing good money after bad. Right, dinner's over, time to get de-soldering that diode pack! Cheers, Richard Link to comment Share on other sites More sharing options...
NonMember Posted October 10, 2018 Report Share Posted October 10, 2018 It's true that a short in the field winding could over-stress the diode pack. If you have a good quality multimeter you should be able to measure the resistance. I'm sure there's a document on the web with the correct value. Link to comment Share on other sites More sharing options...
Badwolf Posted October 15, 2018 Report Share Posted October 15, 2018 On 10/10/2018 at 13:52, rlubikey said: PS: Some people seem to modify the thread title when replying. How do you do that? Richard, to modify the thread title you may find that you have to press edit in the original post (the first one in the thread) and then edit the thread title as tge title and first post appear to be linked. 1 Link to comment Share on other sites More sharing options...
rlubikey Posted November 13, 2018 Author Report Share Posted November 13, 2018 So, just a post script to say I trotted over to Burghfield Starter & Alternator Centre and gave him the offending article. It's a proper Fred+Shed outfit and he certainly gave a damn good impression of knowing his stuff! He was intrigued by Canley's "uprated" 60A alternator - seemingly not an original spec. But he checked it over and it was indeed just the diode pack at fault. The original (I wish I'd kept it) has the diodes just covered in some sort of elastomer with the lead sticking out the top. The replacement has them in ceramic discs, which is how I recall Lucas did them originally. The alternator is good so far, but with winter drawing on I'm not getting the Spit out so much. So, based on this limited time (1 month), I give a thumbs up to Burghfield S&A - we need to use these increasingly rare sort of people more often or we'll loose them altogether! Cheers, Richard 1 Link to comment Share on other sites More sharing options...
Colin Lindsay Posted November 13, 2018 Report Share Posted November 13, 2018 4 minutes ago, rlubikey said: So, based on this limited time (1 month), I give a thumbs up to Burghfield S&A - we need to use these increasingly rare sort of people more often or we'll loose them altogether! Cheers, Richard +1 to that. Link to comment Share on other sites More sharing options...
poppyman Posted November 13, 2018 Report Share Posted November 13, 2018 I will 3rd that. There are loads of these little people about, it's just knowing where to find them and spread the word as Richard has done. Tony. Link to comment Share on other sites More sharing options...
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