Vauxhall Astra H 1.7 Z17DTL CDTi 2005 - Alternator not energising - Fixed #Archived Message
Posted by Paul Foster on June 8, 2009, 6:35 pm
This car has been referred to me by another garage who have fitted a new Battery abd alternator for the original, intermittant fault of, after running the vehicle for a while, the battery voltage drops to 9.3v and the EPS would fail along with the ABS and MIL lights illuminating.
No comms with any system except via EOBD - fault stored for battery voltage.
On investigation I seem to have a problem with the 'exciter' wire (blue) on the alternator. There is 0v on this wire when the ignition is on; 0.2v with the engine running. If I momentarily apply a feed to this wire the alternator cuts in and charges normally until I switch off the engine. This wire shows 1.5v while the alternator is charging.
The other wire (blue/white trace) shows 0.5v K.O.E.O and K.O.E.R until I 'excite' the other wire - Then I have NBV until the engine is turned off.
I have traced these two wires to the under bonnet fuse box and they are intact to this point. I'm assuming the alternator is controlled by the multifunction relay in the U/B fusebox.
I'm hoping that someone has experienced this before to reinforce my opinion that this relay is faulty - any suggestions gratefully recieved!