74009 Posted March 29, 2017 Share Posted March 29, 2017 Hi all, I need a new alternator for my GT/E at the moment as the current one is low on voltage. I'm surprised how hard these are to find compared to other versions - does anyone know of a good supplier in the UK? There seem to be different ratings too - I've seen 45, 55 and 65 A. Anyone know what's normal for a standard GT/E, and if there's any detrimental result in using a higher rating? Thanks and best regards Stuart Link to comment Share on other sites More sharing options...
mantadoc Posted March 29, 2017 Share Posted March 29, 2017 Normal GTE 45A Exclusive got a 55A because of the quads ( 2 extra 60W = 120W / 12V = Approx 10A extra load) No harm in a higher rating. We've fitted Monza engines along with 70A IIRC Link to comment Share on other sites More sharing options...
74009 Posted March 29, 2017 Author Share Posted March 29, 2017 Thanks Mantadoc. Link to comment Share on other sites More sharing options...
H-400 Posted March 29, 2017 Share Posted March 29, 2017 Have you already tried to change the voltage-regulator on back of the alternator? If the bruches are worn they give the same problem, and it is an easy job to fix it yourself. Link to comment Share on other sites More sharing options...
74009 Posted March 29, 2017 Author Share Posted March 29, 2017 Hi H-400, Oh, I didn't know that was even an option - I'll have a look. It was a reconditioned alternator that I fitted a couple of years back so it's not old by any means - the voltage was low right from the very start so I suspect it's more likely to be the regulator than the brushes. Thanks for the suggestion. Best regards Stuart Link to comment Share on other sites More sharing options...
74009 Posted April 9, 2017 Author Share Posted April 9, 2017 Turns out that it's not the alternator, or the voltage regulator, at fault. Just over 14 volts measured directly there, but only 11.9 volts getting back to the battery. Ho hum. Link to comment Share on other sites More sharing options...
mantadoc Posted April 9, 2017 Share Posted April 9, 2017 (edited) If you still have the braided earth lead on the battery consider cleaning connections at both ends and changing as they tend to corrode in the weave. Same goes for the engine earth strap Putting a jump lead from the engine mount (on the engine) to the battery and -ve checking voltage will help diagnose earth strap problems Do not forget that a second jump lead from alternator case can be used to test if it is the weedy alternator earth wire (they fray around the eye) causing the problem. On my car I added an earth wire from battery negative earth lead mount on the body direct to engine years ago. Edited April 9, 2017 by mantadoc Link to comment Share on other sites More sharing options...
74009 Posted April 9, 2017 Author Share Posted April 9, 2017 Hi mantadoc, The braided earth lead and engine earth strap were both replaced quite recently. When I measured the voltage between the +ve terminal of the Alternator and the -ve terminal of the battery (or indeed anywhere else earthed) I got the full reading of just over 14... so it did seem to me that the loss might be occurring somewhere on the +ve side rather than the earth. I'll try what you've suggested above to see if anything pops up... Best regards Stuart Link to comment Share on other sites More sharing options...
mantasrme Posted April 10, 2017 Share Posted April 10, 2017 So the alternator is putting out 14v but you are only seeing 11.9v at the battery. So it could be the power lead from alternator to battery, dirty power terminal on battery or a faulty battery. A dead or dying cell in the battery will suck the power from the system very quickly. Link to comment Share on other sites More sharing options...
Scribe of Lincoln Posted April 11, 2017 Share Posted April 11, 2017 On Wednesday, March 29, 2017 at 10:00, 74009 said: Hi all, I need a new alternator for my GT/E at the moment as the current one is low on voltage. I'm surprised how hard these are to find compared to other versions - does anyone know of a good supplier in the UK? There seem to be different ratings too - I've seen 45, 55 and 65 A. Anyone know what's normal for a standard GT/E, and if there's any detrimental result in using a higher rating? Thanks and best regards Stuart I had the same problem last year and then found a very reasonably priced one at a motor parts shop in Lincoln. I'm away in Blackburn tonight but will dig out the details for you when I get home tomorrow. Link to comment Share on other sites More sharing options...
74009 Posted April 11, 2017 Author Share Posted April 11, 2017 Thank you very much. It is however looking like it's not the alternator at fault - so hopefully I won't need to source one after all. Best regards Stuart Link to comment Share on other sites More sharing options...
Recommended Posts