HI All,

I'm just preping the kit for her yearly MOT and summer driving.

fitted a new battery (increased cranking amps)

started no hassel, did a little check, and the reading when running at idle was only 12.8V across the battery. i'd expected 14.2v....

SETUP:

toyota 4age engine.
Xflow Alternator (lucas type)

Alternator has had the pully from the toyota alternator put on it.


SO:

is the problem,

1) knackered regulator? is there a test and where do i get a new one
2) Knackered alternator maybe from over revving of the alternator (pulley sizes)?
3) Actually no problem and i'm being daft
4) Other?



simple votl meter checks and quick cheap solutions appriciated


Many thanks

no one about today?

You should have around 14.5 volts with engine revs at around 2000rpm & dipped beam on - no other electrics, if battery voltage is not rising from the 12.8 you say you've got then alternator isn't charging.

You're saying Xflow Lucas alternator, so I'm guessing Lucas 17 ACR, IIRC the rectifier is soldered in & is part of the control unit, no particularly simple way of checking without pulling the back off & doing some meter checks to see what you've actually got b4 the control/rectifier. B4 doing that I would check that you have a good supply to the main large Lucar terminals on the alternator, the favourite with these was that the plug became a bit loose & overheated due to the current it transmits, if the terminals look at all burnt, then you need to fit a new plug b4 doing anything with the alternator or it will just repeat fail.
They used to be dirt cheap & it wasn't really worth faffing with internals better just to go for a replacement unit, don't know what sort of money they are nowadays?

hmm, to be frank that was my feeling and new alternator is abotu £40, so not money breaking.

it's located untder the exhaust too, so maybe need to check this over heating and dirt first.

think i have a spare actually in the shed, might just give it a whizz first.

is it possible it's over revved and burnt out?

The Toyota is a lot higher revving than the Kent, I would have thought the pulley ratios weren't dissimilar, but seem to remember race Xflows revving to about 10,000 rpm & I think they ran standard alternators? I would think you have to be holding high revs for long periods to damage the alternator & even then I'd be expecting thrown coils rather than burnt out. All IMHO of course!

good oh, think i'll just get a new alternator then if i haven't got one already.

happy days, simple fix

In the old days with hot Xflos the standard crank pulley was swapped for a smaller dia cast pulley which was usually called the Lotus Twincam pulley but I think was actually an Anglia 105e part.

Back to the alternator most likely worn brushes ---- very very simple to change if the slip rings aren't worn out. Changing the slip ring requires simple soldering (nothing fiddly), the regulator is also easy to change but changing the diodes is best left to somebody used to soldering.

If the alternator diodes are knackered would sugest swaping the alternator for the later Lucas Magneti Marelli a127 which is more modern and a straight swap just make sure you get one with the correct pulley as the pulley to shaft fitting is different.

[Edited on 2/4/12 by britishtrident]

would that be a straight swap or need a connector change?

Standard 3 blade same as older ACR just make sure you get one handed the same way and correct pulley.

ACR alternators you can change from left to right handed --- never tried on the A127 but should be ok.

Might be worth fitting a heatshield between the exhaust and the alternator . My car went through a couple of alternators before fitting a heatshield, since fitting one it's been fine

well been out and tested again,

no change at idle or when revved.

infact no different even if the alternator wasn't connected.

my conclusion is something very wrong in teh alternator, so i'll order a new one, unless anyone has any suggestions.......

think i may have found the problem.......

well chencged bushes made no diference, so wondering what it muight be now.

dammit i'm not good on electrics ND WANTED IT ON THE ROAD AGAIN.

dam caps lock key

I used a Suzuki Vitara alternator and hung it from the inlet side;

Alt sm

are you sure the wiring is correct? I had this issue and it turned out I needed a positive feed to the alternator as well, just a small link from the battery connector to the next pin