Clive Posted November 4, 2010 Share Posted November 4, 2010 My sisters ageing fiesta ('92 "classic" shape thingy) stopped today. Literally. I towed her home, and it turns out the battery is flat. However, I jump started it and it ran and behold only 9V across the battery. No wonder it died with lights on.Anyway, obviously not charging BUT the alternator light wasn't on either. Could a blown bulb here stop the unit charging (have heard that mentioned somewhere)Any pointers so I don't get too much grief would be handy, I want to get on with my spitfire :)taClive Link to comment Share on other sites More sharing options...
beefertoo Posted November 4, 2010 Share Posted November 4, 2010 afaik if the bulb isnt working then it wont charge. as a quick(ish) check if you disconnect and earth the little wire from the back of the alt it should then work and thus mean the alt is toast.beware some later cars have a relay in the circuit just to confuse matters(not sure bout the festa though)craig Link to comment Share on other sites More sharing options...
Nick Jones Posted November 4, 2010 Share Posted November 4, 2010 Yes, in many setups a blown warning bulb will stop it charging (daft isn't it!). Check the bulb. You should also have most of 12v between the little exciter wire and earth with the ignition on and earthing it should light the alternator light.I think that if you connect a temporary wire from battery + to the small exciter wire post on the alternator then it should start charging if healthy.Get that battery on charge immediately or it will sulphate and be useless.NickEdit: If it's a 1.1 valencia engined car that alternator fits a Triumph too! Link to comment Share on other sites More sharing options...
Clive Posted November 4, 2010 Author Share Posted November 4, 2010 Yep it is the ancient 1.1 ohv unit. Now done 55,000 miles :)Battery is on charge and has been since I got it home, and under warrenty too (god bless Halfords and their tradecard)I will have a play in the morning. Need a kip, been working today 8) Link to comment Share on other sites More sharing options...
Richard B Posted November 5, 2010 Share Posted November 5, 2010 Nick_Jones wrote:Yes, in many setups a blown warning bulb will stop it charging (daft isn't it!). Check the bulb. That's why the battery sensed alternators are a better design. Link to comment Share on other sites More sharing options...
Clive Posted November 5, 2010 Author Share Posted November 5, 2010 Yep, fried alternator Zip, nothing.Rummage in garage = near enough "new" version but wrong handed. Undo 3 bolts, twist a bit and do the bolts up. Job done. Oh, and impact wrench to swap the pullies. Handy things those.....Also a quick check revealed an oil top-up of 2 1/2 litres !!!! and 1 1/2 or water for the coolant. The oil pressuer switch is duff too (bulb ok, shorted the connector and it lit up nicely). Think I need a word about maintenance :-/ Link to comment Share on other sites More sharing options...
Richard B Posted November 5, 2010 Share Posted November 5, 2010 cliftyhanger wrote:Yep, fried alternator Zip, nothing.Is the warning light working? Link to comment Share on other sites More sharing options...
Clive Posted November 5, 2010 Author Share Posted November 5, 2010 Perfectly (now)In fact when I put the freshly charged battery on this morning it was glowing dimly them. I guess when the battery was so flat it was so dim I couldn't see it :-/Anyway, new oil switch fitted, dash all lights upm as it should. Oil to last a while, plus water. Think it needs am engineers decoke later, help it feel better. Link to comment Share on other sites More sharing options...
piman Posted November 8, 2010 Share Posted November 8, 2010 Hello Richard,"That's why the battery sensed alternators are a better design."Would you explain the difference?Alec Link to comment Share on other sites More sharing options...
Clive Posted November 8, 2010 Author Share Posted November 8, 2010 I think it is because if the bulb blows, then it will not affect the alternator wiring.Interestingly (or not!) my denso one on the Toledo has the warning light wired up, and an ignition controlled feed too (as well as the battery feed) However, I have not connected the sensinf terminal, and all seems well. Actually very nice little alternatorm, cost about a tenner more than a recon Lucas jobbie, and that was new. Should last forever, and it I sell the car I am keeping the alternator. Link to comment Share on other sites More sharing options...
piman Posted November 8, 2010 Share Posted November 8, 2010 Hello Clive, can you elaborate, I'm trying to understand what differences there are between battery sensed and the other type?Alec Link to comment Share on other sites More sharing options...
Clive Posted November 8, 2010 Author Share Posted November 8, 2010 Doesn't the warning light circuit excite the alternator, or something. Maybe switch the field on? Not too sure really, but seems the later alternators have seperated the functions out, for the better. probably. Link to comment Share on other sites More sharing options...
Richard B Posted November 8, 2010 Share Posted November 8, 2010 Both work the same way, but the battery sensed alternator is not dependant on the bulb being ok.With the normal Euro 3pin connector if the bulb is blown the alternator has no way of telling the correct voltage to output. Link to comment Share on other sites More sharing options...
piman Posted November 9, 2010 Share Posted November 9, 2010 Hello Richard, if the Euro 3 pin is what the Lucas ACR alternators have, then the warning light is the only connection to the regulator?. how is the battery sensed alternator connected?Alec Link to comment Share on other sites More sharing options...
Richard B Posted November 9, 2010 Share Posted November 9, 2010 No I'm talking about the other alternators that were fitted early '70s to the big cars (AC Delco?). They have two plugs. Link to comment Share on other sites More sharing options...
piman Posted November 9, 2010 Share Posted November 9, 2010 Hello Richard, I'm sorry but I'm getting more confused. Would you explain the two types and how they differ in their configuration?Alec Link to comment Share on other sites More sharing options...
Clive Posted November 9, 2010 Author Share Posted November 9, 2010 http://www.delcoremy.com/Documents/Alternator-Service-Manuals/31SI-ALTERNATOR-INSTALLATION-INSTRUCTIONS.aspxDoes that help?I think the main difference is that in both types the alternator needs a reference voltage. In one type it is via the bulb, if that goes then it won't charge. In the later types the light has its own circuit, but the regulator has its own seperate battery voltage wire.OK, not an elegant explanation, and no, I am not an engineer, elecrical or otherwise! Link to comment Share on other sites More sharing options...
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