Alternator output?

toddao · Post by **toddao** » Sun Apr 27, 2008 4:20 pm

There is an alternator for sale here on Ebay that the seller says is for 'BX,ZX and Peugeot diesel models' - it's rated at 80 amps and came from a BX. My alternator is rated at 50 amps however.
Am I correct in thinking that the 80 amp version would be for an air-conditioned model?

Post by **mat_fenwick** » Sun Apr 27, 2008 5:17 pm

Probably(!) as the air conditioned models should have a higher output alternator. When I converted mine I kept the original alternator, which promptly died at the start of a holiday in France. Fortunately I got to a Citroen dealer who even more fortunately had the correct high output alternator in stock at 6 o clock on a Friday afternoon, however at the unfortnate price of 350 Euros!!!
So if this one is a bargain then I would say go for it as it won't overcharge your battery.

toddao · Post by **toddao** » Sun Apr 27, 2008 5:24 pm

Mat, I take it that you have air-conditioning then? At the moment it is a reasonable price - less than a pint of Ale.
When you say it won't overcharge the battery is someone able to explain how this is so, with the higher output etc ?

kermit the frog · Post by **kermit the frog** » Sun Apr 27, 2008 6:38 pm

Hi Todd

It is rated at 80 amps but it will only go to that if the system requires it .
If your car only requires at max load 40 amps then the alternator will cover that EASILY.
What i am trying to say is that it will produce 80 amps if required.
but a 50 amp alternator will overload if trying to keep up with an 80 amp load.
Which is why Matts standard alternator failed when the air conditioning wanted more power than it could produce.

I do hope i hav'nt confused thing's too much.

Regards Kermit

toddao · Post by **toddao** » Sun Apr 27, 2008 7:08 pm

Cheers Kermit!

I reckon I'll go for it anyhow if it stays within the price of say a case of

(€12). It's not new but good as.. and I need one for the TRD.

Post by **mat_fenwick** » Sun Apr 27, 2008 8:37 pm

Yes, mine does have air con, fitted with a lot of guidance from this forum (thanks Tom, AlanS, Jaba, Bernie).
Kermit explained it well, the battery and electrical systems will only draw what they require from the alternator - it's not as if the alternator is 'pumping' 80 amps into the battery. As it is rated at 80A, under normal use it will be working to a lower % of its max output than a standard one and hopefully should last longer. Physical size looks to be the same.

toddao · Post by **toddao** » Sun Apr 27, 2008 8:56 pm

Well, I got it, for two cases of

. Thanks for advice fellas!

jeremy · Post by **jeremy** » Sun Apr 27, 2008 9:31 pm

ZX Diesels have a slightly larger alternator than a BX and it won't fit - certainly DTR Turbo's (sept 1989) - as I found out after about 5 knuckles and some bracket mods.

Vanny · Post by **Vanny** » Sun Apr 27, 2008 9:58 pm

Are you sure Jeremy? I've been reliably informed the ZX, Xantia, XM, 405, most of the 406 and some newer stuff (ie XU engine or derivative) alternators will fit the BX. I currently have a Xantia 1.9TD 75amp alternator on my BX16v and have absolutley no problems with it, its even nicely charged a half flat battery as well. If anything with it internal pump and nice rounded edges it was easier to get into the hole (which is super small on the 16v)

Todd that looks super shiney and super original, i want one (but a 120amp one to run the inverterS)

jeremy · Post by **jeremy** » Sun Apr 27, 2008 11:02 pm

I spent hours trying to get the thing in - would go on the bottom mount but hit the top one. I tried grinding a bit of the bracket away but it was clear that I'd never get it to fit.

My car is 1989 with the big thermostat and the separate fuel filter. The distribution of ancillaries on the ZX is a bit different and the injection pump seems to be mounted in a slightly different place.

Vanny · Post by **Vanny** » Mon Apr 28, 2008 12:39 am

that might be the dubry then, the Xnatia pump is also on a different mount plate, and ive rotated the alternator through 180 degrees (about the pulley) so that it matches the bracket.

Jaba · Post by **Jaba** » Mon Apr 28, 2008 11:36 pm

Aircon BXs did tend to have the higher output alternators fitted as standard.
Not really necessary though, especially as the 80amp ones are much more expensive to buy. Aircon does use a bit of extra electrical power as the twin fans - rad and ventilation - are running most of the time. In traffic on a hot day the high speed rad fans kick in quite often too.
This will use more power but not 30 amps more. A 50 amper will supply over 600 watts which is actually quite a lot of electrical power for a BX.
So I suppose they specify the 80a for this worse case scenario.
I only have 50a on my two aircon BXs and I have never seen a battery charge problem.

The important difference between alternators to be aware of is to be sure you get a 5 groove pulley if thats what you have fitted already.

So well done Toddao you got a bargain.

toddao · Post by **toddao** » Tue Apr 29, 2008 6:36 am

Jaba,

you've got two air-conditioned BXs ? - you're a brave man! This alternator has a five groove pulley and the car it's for has four but I already investigated swapping the pulleys and this seems possible ( unless anyone knows otherwise?)
I think it went for such a low price because it was one of those patchy listings - I had to ask him for all the technical details which took ages to get a reply. He hadn't listed the output.
If there's any reason that I can't fit it, I'd be prepared to swap for a good 50A with one of you air-con boys!

Vanny · Post by **Vanny** » Tue Apr 29, 2008 10:29 am

dont bother swapping the pulley, just use the teeth you have. I've got a 6 tooth pulley on the xantia alternator on the valver but only a 5 tooth belt, makes no real difference.

Post by **docchevron** » Tue Apr 29, 2008 1:59 pm

However, should you wish to change the pulley it's easy enough, although the easiest way to undo the nut is to buzz it off with an impact wrench..