I have this alternator and its not working - purchase new and hardly used - about 50 miles.

I have done a test and alternator is not charging battery - can someone help me re wiring the alternator.



At present i have wired the positive wires to the position marked with a white sticker (connected to the silver bolt)and wired the what i assume is an earth that pushes on to position marked with a yellow sticker.

What concerns me is there is a space for a spade connector where the green sticker is and also space for another connection where the blue sticker is - marked on the unit with the letter "W".

Am i going wrong somewhere ??

 

You have the output right, I.E positive onto the correct terminal 'B', the push on connector you talk of will be a blue wire and this connects to terminal 'D'. This is the battery light, and is part of the charging circuit as well.

This excites the field windings which starts the charge process, revving to around 4K will also work.

Make sure your battery light comes on when ignition is switched on I am guessing it won't and this is why the there is no charge, and it's not uncommon for the blue wire to break.

W is not used this is for rev counters on diesels and for electric chokes.

Martin

 

the blue sticker and green sticker is for a small black box with a spade connector that should be on your old unit? Diode I think its called? Not exactly sure that what it called but that is what they are for dont think you need them tho, your correct with the other two wires. Im having same problem. It wasnt charging then had auto elec out he sorted it out just had rebuild done and now all wires look correct but aint charging and dont fancy paying auto elec again so hopefully someone can help you out so I can nick some info lol

 

Thanks - just to clarify is terminal "D" the one marked with a yellow sticker in my pic ? or is it the spade terminal ? or is the spade terminal left with no connection.

Also when ignition is on the battery light does come on as far as i remember

p.s. yes the push on wire is the blue wire

 

The green spade is not for the diode, that is for a suppressor but that isn't a fundamental component but ideally you would have one.

Yes the blue wire is where the yellow sticker is.

Martin

 

am having same problem then as my battery light also comes on and all wires are connected. Sorry about the diode wasnt sure what it was called

 

If the battery light comes on with ignition then thats ok, check the output at your white terminal with the engine running.

Martin

 

So i summary its appears that I have it wired correctly - my next question then - is there any way i can test the alternator whilst its off the car ? I want to exhaust the fact that the alternator is faulty before i go ahead and buy another - are there any other checks i can do to try and determine the fault ?

 

No unless you have a bench setup you can test it on with something to drive it. As I say check the power out that terminal with car running if your not getting any power here then you know its an alternator problem, if you are then it indicates there is a wiring/earthing problem further down the line.

Martin

 

As suggested I took the push on connector off and it appears to have corroded slightly - i have cleared the wire back to a good bit and reconnected using an "o" ring terminal and wired and refitted and all appears to be good.

Battery reads 12.96v when engine off and 14.22v when engine running and does not drop when engine revved so fingers cross problem appears to have been solved.

Thanks Martin and everyone else for their advice - saved me £70 for a new alternator that in the end was not the problem.

thanks again
Stuart

 

No problem glad it's sorted, for future reference as I say revving to around 4K will also start charging.

Martin