alternator wiring

[foshi]

my herald came fitted with a alternator with 2 plugs in the back , it is playing up bearing noise not charging , how can i change the wiring to a single plug alternator a lot less money with the single plug paul.

[GrahamB]

I suggest that you study the wiring diagram for a model fitted with the single plug alternator; both large spade terminals connected directly to the battery +ve and the smaller spade terminal connected to the warning lamp (which must not be an LED).  The wiring diagram suggests in theory it should be quite easy but in practice??

[foshi]

ok graham

8 minutes ago, GrahamB said:

I suggest that you study the wiring diagram for a model fitted with the single plug alternator; both large spade terminals connected directly to the battery +ve and the smaller spade terminal connected to the warning lamp (which must not be an LED).  The wiring diagram suggests in theory it should be quite easy but in practice??

will do was hoping was going to be a simple case of joining wires paul

[chrishawley]

 

3 hours ago, foshi said:

2 plugs in the back

Wonder if the attached diagram might provide some illumination. Assuming you currently have an ACR series alternator then the pin-outs would be one of the three illustrated. I hadn't noticed before that while the ACR standard connections had an earth lead to earth the Euro connection didn't. So (obviously) if using a Euro connector the earth would not be used.

 

 

[foshi]

12 hours ago, chrishawley said:

 

Wonder if the attached diagram might provide some illumination. Assuming you currently have an ACR series alternator then the pin-outs would be one of the three illustrated. I hadn't noticed before that while the ACR standard connections had an earth lead to earth the Euro connection didn't. So (obviously) if using a Euro connector the earth would not be used.

 

 

thank you that helps a lot paul

[Writer2023]

This is a really useful thread, thanks. However, I'm still having some trouble understanding when I look at what I have to work with on my GT6 MK3. I am chaning my alternator. My new one is what looks like European Terms, upgrading from the standard terms - as per your kindly posted wiring diagram, thanks Chris.

However, it seems I've got more than three wires, and I'm not sure which is which. Remember I'm a newbie please guys. Electrics always scare me a little to be honest. 

 

I would really appreciate any help at all. I ordered one of the plugs you see in the pictures. I suppose what I'm asking is which three cables do I put in them, and what do I do with what's left over?

 

 

[johny]

First thing is to download the Triumph workshop manual for GT6/Vitesse from this site which is kindly free: vitessesteve.co.uk

Then find the wiring diagram for your car on page 6.506 and compare with the diagram on 6.508 which looks like the one for your car fitted with the later alternator...

 

[chrishawley]

For a Euro style alternator it can be lookeed at this way: Only two wires are required; a heavy brown wire to take the power from the alternator to the battery (via the common post on the starter solenoid) and a thin wire to excite the fields on the alternator which should be a brown/yellow.

Thus; to convert to Euro from standard battery sensing the heavy brown wire is connected to either of the large terminals in the new terminal block. It doesn't matter which since the two of them are common ('piggy back'): It's just that having two of (effectively) the same terminal gives a option to run a second heavy brown wire for high load situations (only rarely applicable) and the extra terminal gives a bit of extra grip of the terminal block in the alternator and thus more resistant to working loose (supposedly). 

The thinner brown/yellow wire will now be connected to the small termninal in the block. But a confirmatory test to prove the wiring has not undergone some modification in a pervious life is to, with the ignition on, briefly touch the brown/yellow down to any earth point and observe that the ignition warning light comes on as touched . If so, all is good. If not then pondering would be required.

That should leave left over i) a short loop of brown/yellow on the existing small terminal - this has no function in the Euro system so discard. ii) The thin brown to the existing small connector now has now function but it will still have 12 volts on it. So cut and exposed copper short to the insulation, fold back on itself and insulate with insulating tape or heat shrink (HS is better). Tuck away anywhere handy. iii) If there is a black wire from the existing alternator to earth then discard. On the Euro arrangement the alternator is earthed through its body so no earth wire is required.

Hopefully that fills in some of the details.

[Writer2023]

Thank you for this... I will do this as soon as my new connector arrives. Many thanks for the help. I'll let you know if it works.

 

 

[Writer2023]

So I attached these two cables to the new alternator. The car starts fine. Got rid of the loop cable and then left with the one thin brown cable, which I believe isn't necessary, that's right, yes?

[Writer2023]

I'd just like to say thanks to you Chris, you really simplified this for me. Now I have an issue with the OS read indicator to sort out tomorrow and I should be able to go road testing whilst there's still some summer left!

[chrishawley]

11 hours ago, Writer2023 said:

left with the one thin brown cable, which I believe isn't necessary, that's right, yes?

Correct: To confirm; the TBW would have been for battery sensing of voltage but not relevant any more for an ACR alternator that senses it's own voltage (machine sensing). Hopefully light will be an easy fix.