Hi Guys
Car: Corsa 1.7D 1998 With 149'999 Miles on the clock. (and quite possibly a few more of it - I was young and naive when I bought it.)
I was driving home last night when the alternator light (idiot light) came on, as I was only 5 mins from home I turned off all non-essentials and carried on. Once in the light today I have had a look, it appears that the alternator is being driven fine from the engine... No evidence of slippage or lack of vacuum for the brakes - the vacuum exhauster is mounted on the rear of the alternator.. The light however remains illuminated.
With a multimeter across the battery I have found that the battery is holding around 12.6v with the engine switched off, and this rises to 13.5 volts with the engine turned on. (however this voltage rises from 12.9V rather slowly at around 0.01v per second).
Revving the engine at anything more than tick over causes the alternator warning light to glow _slightly_ brighter.
I have thus concluded that the alternator is supplying a small charge to the battery, but is hardly sufficent to sustain it and thus it must be repaired.
Now taking my schoolboy knowledge of alternators I am guessing there could be a couple of problems,
- The Regulator is knackered - and regulating too low?
- One or More sets of the three diodes - one for each stator winding? does that sound right? are knackered?
- There is a Problem with the excition of the Stator windings?
Problem 1 & 2 i have heard people talk about changing and i have seen repaired in a workshop, and i feel confident having a go myself. Problem 3 i dont think i would even touch!
However before i begin taking things to bits i was wondering if anyone has a workshop manual or any expirence in working with this alternator?
Does the presence of a vacuum exahuster cause any difficulties in dealing with this product is there any preventitve maintainance i should lavish upon this beast whilst it is accessable???
Given that the unit has been as far as i can tell on the car since it was built without and attention (certainly for the last 100k i am thinking it would be prudent to replace the bearings whilst the unit is on the bench is this something an average amateur could manage?
Any comments.?
Scans of a Workshop manual would be rewarded with 5 × £1 beer vouchers being deposited in a paypal account!.
Kind Regards
Tom