How can I tell what Alternator I have

[nesty]

I have a 1984 Holdsworth. I gather the orignal Alternator would be 45amps? I've looked through old bills and service history, it doesn't mention anything about a Altenator change, though surely been changed from the orignal.

Can I tell (without taking it off) by the S/N on the Alternator, what Amp it is?

[kevtherev]

there might be a sticker on it.. what colour is it?

Alternators rarely cause grief.. but the renewable rectifier/brush pack does wear out.
Situated on the back of the unit and removed by undoing two screws.

they cost a tenner

[nesty]

I am going to poke my head in the engine bay on Sunday to view.

I've got a more detailed thread in Modified section. Though in short; I've installed a intelligent Split relay charger from Raw Compenents. Along with a big I.C.E system (2 amps and 2 subs). Took it for a spin yest, (I got twin dash voltmeters), from what I could see not much charge going back in. The Alternator might be a 45amp version?

[Red Westie]

the renewable rectifier/brush pack does wear out.
Situated on the back of the unit and removed by undoing two screws

I think you mean regulator/brush pack.....

There is normally a pink/red sticker on Bosch alternators identifying the part.
Martin

[bigherb]

There is normally a pink/red sticker on Bosch alternators identifying the part.
Martin

Or a green one

[nesty]

OK cool thanks for this. Didn't have time to look today. If the Alternator is 45amp. Is a 90amp one a straight forward replacement for match up?

[Oldiebut goodie]

I am going to poke my head in the engine bay on Sunday to view.

I've got a more detailed thread in Modified section. Though in short; I've installed a intelligent Split relay charger from Raw Compenents. Along with a big I.C.E system (2 amps and 2 subs). Took it for a spin yest, (I got twin dash voltmeters), from what I could see not much charge going back in. The Alternator might be a 45amp version?

You will only get charge going in if you have already taken it out! (ie using it without the engine running for a long period)
The voltmeter is not going to tell you as much as an ammeter would.(although helpful)
You should be concentrating more on the amps that you have going into the battery rather than volts - but only if the battery is discharged. If the battery doesn't need the amps why upgrade the alternator?
As I've said before - do you use a 45 amp battery charger when you charge a battery up off of the vehicle. A 45A or 65A alternator is adequate.