1150GS Alternator Swap

[Pete D]

Chaps

Having just received my 'new' alternator, it seems I have a 40A one fitted and a 50A one to fit.....

I understand that they are fully interchangeable, but the plug/rear cover are different. So.....do I take the regulator and back cover offf the old and match the current connectors, or change the connectors to fit the new?

If it is the former, I rather hope that it is not the regulator that has gone kaputt!!

Cheers in advance

Pete

 

[Steptoe]

The alternators have different fittings depending the year, not the output.

Change of connector/fittings was 2003ish

 

[Pete D]

Wonder if the 'broken' bike was a late 2002, so a 2003 model.....

I'll ask......

If so, any way round it?

Cheers

 

[Ian J Hartley]

Sounds like your original is a Denso and your replacement is Bosch. The voyage regulators are different and doubt interchangeable.

You will probably find you don't need the green wire for the Bosch, as it is the positive for the denso voltage regulator, the Bosch is connected internally. Tape it up.

Conect the big red to the big terminal and the blue wire to the other terminal and they should work.

 

[Pete D]

You Sir are correct in that the old is a Denso and the new a Bosch....

I'll try just connecting the blue up.

Thanks.

 

[Ian J Hartley]

Just remember, the green wire is 12v live via the ignition switch. Make sure you tape it up well, and tie it into the loom so it can't chafe.

 

[Pete D]

And........

Success!

Less than one second after start the battery light goes out. The battery voltage rises to late 13s, then falls to a steady state of about 13.2V....

Think that has it sorted.

Thanks

Pete

PS. I've left the connector block 'as is', and plugged the blue onto the alternator; the green wire is 'buried within the block' and held captive in mid air. Should have absolutely no chance of chafing or touching anything else.