peejay4A Posted August 3, 2016 Report Share Posted August 3, 2016 (edited) What does the battery voltage do as you rev her up Dick? Edited August 3, 2016 by peejay4A Quote Link to post Share on other sites
Lebro Posted August 3, 2016 Report Share Posted August 3, 2016 The 1.3V reading would be correct if the alternator was not giving a charge, there needs to be a large votage difference across the warning light for it to come on - 12V from ign circuit, & 1.3V on the other side. The issue here seems to be that you need to rev to 2000 before the alternator "switches on". When this does eventually happen the alternator generates the 12V (nom) on the alternator side of the warning lamp, & it goes out. The part which looks wrong is that the alternator fails to supply enough volts to keep it's self going when returning to tickover. So, could be the rectifier pack at fault, is the alternator pulley the correct (small) diameter ? is your tickover slower than normal (600 - 800 RPM) Bob. Quote Link to post Share on other sites
peejay4A Posted August 3, 2016 Report Share Posted August 3, 2016 I suspect that a field pack diode has gone s/c. Quote Link to post Share on other sites
ianc Posted August 3, 2016 Report Share Posted August 3, 2016 James Christie, living on the Gulf of Morbihan in France, had difficulty with a Moss alternator kit in 2010/2011, and, following a lot of emails which finally got the installation working satisfactorily, James and I concocted an article about the Moss alternator kit, and this was published in TR Action 248 (March 2011). Might prove helpful. If you haven't got the article, email me for an MS-Word version - email address on p82 of TR Action. Ian Cornish Quote Link to post Share on other sites
R Surrey Posted August 4, 2016 Author Report Share Posted August 4, 2016 AllHave checked few things following latest mails. Pulley size is 4.5 dia (alloy). When see the conversion leaflet that have I see this is for competition use only and 2.75 would be normal size. Is this part of the problem! Tickover is at a steady 700rpm (I have just fitted a lightened flywheel as had g/box out due to sheared crossshaft pin, prior to this tickover was 800rpm). When check battery volts get reading of 12.55v when engine switched off , 12.55v on tickover and about 13.7v at high revs (hopefully have taken this reading correctly). Just need to go and see what fanbelt I am running on with the 4.5 pulley. I will e mail Ian to get a copy of the article he mentions.Regards Dick Quote Link to post Share on other sites
ChrisR-4A Posted August 4, 2016 Report Share Posted August 4, 2016 Dick, the competition pulley is bigger so you don't over Rev the alt but at low revs output would probably be insifficient. Comp engines would prob tick over at nearer 1000 rpm so no prob. Battery voltage is a bit low, fully charged is usually about 12.68 but the pulley is prob not helping to get it fully charged. Quote Link to post Share on other sites
peejay4A Posted August 4, 2016 Report Share Posted August 4, 2016 Agree. Wrong pulley. Quote Link to post Share on other sites
Lebro Posted August 4, 2016 Report Share Posted August 4, 2016 +1, but on charge voltage should be nearer 14.5V Bob. Quote Link to post Share on other sites
R Surrey Posted August 4, 2016 Author Report Share Posted August 4, 2016 All, thanks for all help, just ordering a new pulley ,0nce fitted will let you know outcome Regards Dick Quote Link to post Share on other sites
R Surrey Posted August 6, 2016 Author Report Share Posted August 6, 2016 All, another frustrating day. New pulley (2.75) arrived from Moss today and fitted this without any issues. Problem now is that with the small fan fitted and fan belt GCB10975 used the alternator sits to far away from the block that the conversion bracketry to tension the belt fouls the wheel arch. ie belt is toolong despite the Moss paperwork I have for the installation saying that this is the belt to be used with the 2.75 pulley. I intend to speak to Moss on Monday to see if they have a shorter belt as looking at their website cannot see what differences are between belts. The only other one they appear to have is GCB11088 relating to TR5/6 but I don't know if it is shorter or not.Any thoughts appreciated Thanks Dick Quote Link to post Share on other sites
R Surrey Posted August 6, 2016 Author Report Share Posted August 6, 2016 All, looks as if I have been fitting the adjustment bracket the wrong way round. Have just read the article that Ian Cornish has sent me and I am off to the garage to have another look at fixing arrangement. Report back later Dick Quote Link to post Share on other sites
RogerH Posted August 7, 2016 Report Share Posted August 7, 2016 Hi Dick, Halfords do a whole series of thin (modern) belts - They will certainly have one that will fit correctly. Roger Quote Link to post Share on other sites
R Surrey Posted August 7, 2016 Author Report Share Posted August 7, 2016 Roger, thanks for that however having had a further attempt to fix alternator it is clear there is a problem. Have just checked on line with Moss catalogue and can clearly see that both alternators that I have are for a TR5/6. The TR4 alternator fixing for the adjustment bracket is in a completely different location. How I ended up with this mismatch of components I just don't know. Feel sure that when get a new alternator it will solve problem of belt size/small pulley. I'll ring Moss tomorrow just to check.Thanks Dick Quote Link to post Share on other sites
RogerH Posted August 7, 2016 Report Share Posted August 7, 2016 Hi Dick, the 5 & 6 have right hand Alts as they are fitted on the left of the engine. The 4/4A have lefthand alts fitted to the righthand side. I think it is to do with how the adjuster is positioned. You can dismantle your Alt and fit it the correct way round by rotating the back plate. Roger Quote Link to post Share on other sites
R Surrey Posted August 8, 2016 Author Report Share Posted August 8, 2016 All, thanks very much for everyones help. in resolving this issue. Followed Rogers advice and rotated the alternator casing. Fitted back into car without problem connected electrics back in place and fired it up. EURIKA warning light went straight out with ammeter showing positive charge. On tickover warning light stays off. A great result so once again thanks to all. Regards Dick Quote Link to post Share on other sites
ChrisR-4A Posted August 8, 2016 Report Share Posted August 8, 2016 You know what really pisses me off guys, I can often help to solve other people's problems easier than my own???????? Quote Link to post Share on other sites
RogerH Posted August 8, 2016 Report Share Posted August 8, 2016 Hi Chris, I'll sort yours if you sort mine - best of luck Roger Quote Link to post Share on other sites
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