Alternator connections

[KemppiFrog]

Hi All
While this is electrical, it is auto rather than domestic, so hope it is OK to slip it in here?

Neighbour has a Mazda 6 2.0 diesel from 2007. Conked out and he thought battery, so changed it. Then told it is alternator. Since he has some sort of eye problem that means computors are a no-no, I looked up a spare, as the price he mentioned was a bit gaspy.
You can see where this was going..... I got the unit and set to. I right pig for access, but got them swopped over and was connecting up when the field plug wouldn't fit.

Old
and

New.
Of the three terminals in the old, only the left two are used , with a red to the left and a green to the centre. Now scratching my head as to which way round the new one needs connecting.

Any one a bit more savvy on this have an idea? Pretty please

KF

 

[8ob]

Off out now, if nobody has come up with the answer by the time I come back I will look it up in a reference book ( bible) I got from Woodautos yonks ago. All the plug configurations/terminals are listed.

Bob

 

[Barking Mat]

Got the model number ?

 

[KemppiFrog]

Hi 8ob & Mat
The new one is a Lucas LRAO2309

And the old, a bit damaged label with no name, but a big 7 to the left then RF7JA and below that ABTB6561. I expect it is original.

Thanks for taking an interest, my limited alternator wiring knowledge is big plus to bat. and exciter, which I would expect to be red? Might the green be revs?
KF

 

[premmington]

Hi 8ob & Mat
The new one is a Lucas LRAO2309

And the old, a bit damaged label with no name, but a big 7 to the left then RF7JA and below that ABTB6561. I expect it is original.

Thanks for taking an interest, my limited alternator wiring knowledge is big plus to bat. and exciter, which I would expect to be red? Might the green be revs?
KF

Sounds like you bought the wrong alternator (from EuroParts?)

 

[Barking Mat]

You've got a big stud for +ve yep ? You got a -ve stud or is it earthed through the mountings ?

If so, you can't bugger it up if they're connected.

Ones (red) is probably excitation, I'd imagine green is tacho ?

Get @8ob to verify.

 

[Barking Mat]

 

[KemppiFrog]

Sounds like you bought the wrong alternator (from EuroParts?)

Got it from Mr Auto. It has two big bolts to mount it (tension by a separate pulley) and looks identical to the original, apart from the socket.
Earth is via the mounting, just a big terminal for positive & the two wire socket (spindly wires) No markings by the socket.

Mat, like your diags, but a bit ancient?? And the Alt is nothing like the examples.

 

[keithski122]

I'd imagine if its got the wrong connector then its the wrong alternator.
When I owned mazda cars I always used to get spares from http://www.mazdasparesuk.com/ so might be worth giving them a call.I know when the alternator went on my 323 there was a choice but they had them on the shelf cheaper than getting mine rebuilt.

 

[Barking Mat]

As long as the big +ve is in the right place, you can't bugger them up in my experience, I've wrongly wired them up before, no tacho and battery light, swapped them round, and everything's fine.

That's my experience, and a disclaimer.

I'd imagine if its got the wrong connector then its the wrong alternator.
When I owned mazda cars I always used to get spares from http://www.mazdasparesuk.com/

Yeah, but we swap all kind of similar alternators in and out, at the end of the day, an alternator is an alternator, the number of times I've put the wires in the wrong place...

As long as the big +ve is in the right place I don't think you can bugger them up.

It's running them not connected to a battery which kills them from my understanding.

Usual disclaimer.

 

[keithski122]

Thing is now with ecu controlled charging an alternator is not an alternator.Imagine the pain if you put the wrong one on and bugger up the ecu just for not fitting the correct one.

 

[Barking Mat]

Thing is now with ecu controlled charging an alternator is not an alternator.Imagine the pain if you put the wrong one on and bugger up the ecu just for not fitting the correct one.

Tis a faire point.

 

[m_c]

It's the wrong alternator.

Given the age, and the 3 terminals, it's likely to be an early smart* charging system.

*smart is quite a loose term for that era. It was basically switchable output, not like a modern system where output/voltage is continually changing.

 

[Pigeon_Droppings2]

May help...on the rx7 site (maybe it's similar...maybe it's not). Personally I'd want to match it all up correctly before "having a go"

Seems like one is 12v and other is dash lamp...is the S just the power for the dash lamp/gauge maybe?

 

[KemppiFrog]

It's the wrong alternator.

Given the age, and the 3 terminals, it's likely to be an early smart* charging system.

*smart is quite a loose term for that era. It was basically switchable output, not like a modern system where output/voltage is continually changing.

Only two of the three of the original are used.

 

[KemppiFrog]

May help...on the rx7 site (maybe it's similar...maybe it's not). Personally I'd want to match it all up correctly before "having a go"

Seems like one is 12v and other is dash lamp...is the S just the power for the dash lamp/gauge maybe?

View attachment 363420

It is very like your S6, though, as in the photo in my initial post, the socket is as the S5.
Thanks for the diag.
KF

 

[Pigeon_Droppings2]

Thanks for the diag.

No problem...I've always wondered what the extra plug does on alternators so I sort of got interested.

So this is what I've found:
The "S" connector is for the alternator to read the battery voltage (and work out if it needs more charge maybe?)
The "L" is a feed to the alternator light on the dash.

So all you really need to know is which is which....could you simply feed 12v to each and see which triggers the dash light? That still leaves the issue of working it out on the new one of course....but at least you'd be half way there as you'd know what the car loom is.

Sorry I just realised...you already knew the red/green on the loom

The correct 12v feed will influence the charge output so maybe thats a way to work it out?

 

[gt6s]

Thing is now with ecu controlled charging an alternator is not an alternator.Imagine the pain if you put the wrong one on and bugger up the ecu just for not fitting the correct one.

Indeed ! The socket on the alternator shown is SMART ALTERNATOR. Not really to be messed with. Not the same as a conventional two / three wire alternator.

 

[Pigeon_Droppings2]

Not the same as a conventional two / three wire alternator.

Sounds like the correct answer may be...just buy the right part?

 

[premmington]

It's the wrong alternator.

Given the age, and the 3 terminals, it's likely to be an early smart* charging system.

*smart is quite a loose term for that era. It was basically switchable output, not like a modern system where output/voltage is continually changing.

+1 for the above.

Ford/Mazda were first in with "smartcharge" tech'