Alternator 2 pin or 3 pin

lesternester · 4th February 2018, 13:40

My 2003 MG ZT diesel has stopped charging,the battery light has come on and the night before this the lights were fading up and down, so i am assuming it needs a regulator/brushes.(i have a battery charge indicator plugged into the lighter socket and when the battery light does go out for a minute or two,it does go over the 14v mark but whith the light on its showing 11.5v).
The lead to the alternator is a 3 pin but there is only 2 pins on the alternator,have been looking on ebay and some of the alternators that have a 3 pin plug also have 3 pins on the alternator and other only have 2 like mine, does it matter which one i get as long as it accepts a 3 pin plug.
Thanks.

MSS · 4th February 2018, 14:53

the regulators are different for the two versions, so it does matter.

It is easy enough to check which you have with a telescopic mirror.

Devilish · 4th February 2018, 15:30

You can plug a 2 pin loom plug into a 3 pin alternator socket because it just does not use pin 3, I have fitted them. But you cannot plug a 3 pin loom connector into a 2 pin alternator socket because it needs pin 3.

You need a 3 pin alternator

lesternester · 4th February 2018, 16:01

Thanks for the replies but maybe i'm not explaining my problem clearly enough,the plug on my wiring loom has 3 female connectors but the alternator only has 2 male connectors and a blank space for the third one,but when looking to buy another alternator some of them are the same as mine with 2 males and a blank and others have 3 males,both of these are known as a 3 pin alternator due to the wiring loom plug being able to take three pins.(i know there are 2 pin alternators but the wiring loom for these only have a 2 pin female socket and only 2 male pins on the alternator and has a different shaped socket).
So can i use an alternator that has three male pins, as my wiring loom plug has three female connectors or do i need one the same as i have got,with 2 male pins and a blank space or doesnt it matter.
Help would be appreciated as i wouldnt want to buy the wrong one.

lesternester · 4th February 2018, 16:29

Thanks for the replies but maybe i'm not explaining my problem clearly enough,the plug on my wiring loom has 3 female connectors but the alternator only has 2 male connectors and a blank space for the third one,but when looking to buy another alternator some of them are the same as mine with 2 males and a blank and others have 3 males,both of these are known as a 3 pin alternator due to the wiring loom plug being able to take three pins.(i know there are 2 pin alternators but the wiring loom for these only have a 2 pin female socket and only 2 male pins on the alternator and has a different shaped socket).
So can i use an alternator that has three male pins, as my wiring loom plug has three female connectors or do i need one the same as i have got,with 2 male pins and a blank space or doesnt it matter.
Help would be appreciated as i wouldnt want to buy the wrong one.

MSS · 4th February 2018, 16:32

The two alternators - 2 pin and 3 pin - are interchangeable.

But, the 2 pin alternator is 120A whereas the 3-pin one I believe is only 100A or 110A.

I would buy the 2-pin one given a choice.

If you have the time, why not get your current one rebuilt? There is a place in Ipswich that I can recommend but they do not do a postal service.

lesternester · 4th February 2018, 19:17

[QUOTE=mss;2592143][I]The two alternators - 2 pin and 3 pin - are interchangeable.

But, the 2 pin alternator is 120A whereas the 3-pin one I believe is only 100A or 110A.

I would buy the 2-pin one given a choice.

If you have the time, why not get your current one rebuilt? There is a place in Ipswich that I can recommend but they do not do a postal service.

Cheers ,will get it off and try match it with a like for like and play safe.

COLVERT · 5th February 2018, 10:55

COLVERT · 5th February 2018, 10:56

DMGRS · 5th February 2018, 12:00

You need the 2 pin. We have them here:
https://www.dmgrs.co.uk/collections/...-and-yle102500

It's worthy of note that while this fixes about 4 out of 5, the 1 out of 5 will have another fault such as a failed winding or completely worn slip rings.
We're happy for you to return of course, if this is the case.

4th February 2018, 13:40	#1
lesternester Newbie MG ZT Join Date: Feb 2015 Location: Norfolk Posts: 15 Thanks: 1 Thanked 0 Times in 0 Posts	Alternator 2 pin or 3 pin My 2003 MG ZT diesel has stopped charging,the battery light has come on and the night before this the lights were fading up and down, so i am assuming it needs a regulator/brushes.(i have a battery charge indicator plugged into the lighter socket and when the battery light does go out for a minute or two,it does go over the 14v mark but whith the light on its showing 11.5v). The lead to the alternator is a 3 pin but there is only 2 pins on the alternator,have been looking on ebay and some of the alternators that have a 3 pin plug also have 3 pins on the alternator and other only have 2 like mine, does it matter which one i get as long as it accepts a 3 pin plug. Thanks.

4th February 2018, 15:30	#3
Devilish Been round the block 75 Tourer Join Date: Apr 2009 Location: Cannock Posts: 4,125 Thanks: 3 Thanked 189 Times in 121 Posts	You can plug a 2 pin loom plug into a 3 pin alternator socket because it just does not use pin 3, I have fitted them. But you cannot plug a 3 pin loom connector into a 2 pin alternator socket because it needs pin 3. You need a 3 pin alternator __________________ If at first you don't succeed, hide the evidence

5th February 2018, 12:00	#10
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,320 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	You need the 2 pin. We have them here: https://www.dmgrs.co.uk/collections/...-and-yle102500 It's worthy of note that while this fixes about 4 out of 5, the 1 out of 5 will have another fault such as a failed winding or completely worn slip rings. We're happy for you to return of course, if this is the case. __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

4th February 2018, 14:53	#2
MSS This is my second home Rover 75CDT, Jaguar XF-S 3.0V6, V'xhall Omega V6 Estate, Twintop 1.8VVT, Astra Estate and Corsa 1.2 Join Date: Dec 2007 Location: Suffolk Posts: 7,085 Thanks: 283 Thanked 624 Times in 440 Posts	the regulators are different for the two versions, so it does matter. It is easy enough to check which you have with a telescopic mirror.

4th February 2018, 16:01	#4
lesternester Newbie MG ZT Join Date: Feb 2015 Location: Norfolk Posts: 15 Thanks: 1 Thanked 0 Times in 0 Posts	Thanks for the replies but maybe i'm not explaining my problem clearly enough,the plug on my wiring loom has 3 female connectors but the alternator only has 2 male connectors and a blank space for the third one,but when looking to buy another alternator some of them are the same as mine with 2 males and a blank and others have 3 males,both of these are known as a 3 pin alternator due to the wiring loom plug being able to take three pins.(i know there are 2 pin alternators but the wiring loom for these only have a 2 pin female socket and only 2 male pins on the alternator and has a different shaped socket). So can i use an alternator that has three male pins, as my wiring loom plug has three female connectors or do i need one the same as i have got,with 2 male pins and a blank space or doesnt it matter. Help would be appreciated as i wouldnt want to buy the wrong one.

4th February 2018, 16:29	#5
lesternester Newbie MG ZT Join Date: Feb 2015 Location: Norfolk Posts: 15 Thanks: 1 Thanked 0 Times in 0 Posts	Thanks for the replies but maybe i'm not explaining my problem clearly enough,the plug on my wiring loom has 3 female connectors but the alternator only has 2 male connectors and a blank space for the third one,but when looking to buy another alternator some of them are the same as mine with 2 males and a blank and others have 3 males,both of these are known as a 3 pin alternator due to the wiring loom plug being able to take three pins.(i know there are 2 pin alternators but the wiring loom for these only have a 2 pin female socket and only 2 male pins on the alternator and has a different shaped socket). So can i use an alternator that has three male pins, as my wiring loom plug has three female connectors or do i need one the same as i have got,with 2 male pins and a blank space or doesnt it matter. Help would be appreciated as i wouldnt want to buy the wrong one.

4th February 2018, 16:32	#6
MSS This is my second home Rover 75CDT, Jaguar XF-S 3.0V6, V'xhall Omega V6 Estate, Twintop 1.8VVT, Astra Estate and Corsa 1.2 Join Date: Dec 2007 Location: Suffolk Posts: 7,085 Thanks: 283 Thanked 624 Times in 440 Posts	The two alternators - 2 pin and 3 pin - are interchangeable. But, the 2 pin alternator is 120A whereas the 3-pin one I believe is only 100A or 110A. I would buy the 2-pin one given a choice. If you have the time, why not get your current one rebuilt? There is a place in Ipswich that I can recommend but they do not do a postal service.

4th February 2018, 19:17	#7
lesternester Newbie MG ZT Join Date: Feb 2015 Location: Norfolk Posts: 15 Thanks: 1 Thanked 0 Times in 0 Posts	[QUOTE=mss;2592143][I]The two alternators - 2 pin and 3 pin - are interchangeable. But, the 2 pin alternator is 120A whereas the 3-pin one I believe is only 100A or 110A. I would buy the 2-pin one given a choice. If you have the time, why not get your current one rebuilt? There is a place in Ipswich that I can recommend but they do not do a postal service. Cheers ,will get it off and try match it with a like for like and play safe.

5th February 2018, 10:55	#8
COLVERT This is my second home R75 Saloon. Join Date: Feb 2009 Location: France/or Devon. Posts: 14,003 Thanks: 3,851 Thanked 2,167 Times in 1,816 Posts

5th February 2018, 10:56	#9
COLVERT This is my second home R75 Saloon. Join Date: Feb 2009 Location: France/or Devon. Posts: 14,003 Thanks: 3,851 Thanked 2,167 Times in 1,816 Posts