Subpage of MembersPage/MarcellGal/PowerAndTraction
This engine has a 110A Bosch alternator, driven by the outer V-belt from the 3-belt crankshaft pulley.
Alternator connections
- a THICK red (obviously positive) wire with 8mm ring connector. I cleaned the connector surface before securing. In my install +12V (always live) coming from the starter mains. I hope this is right
- the alternator body must be the ground
- there is a small ring-connector, wire is broken off on my engine harness. Not sure what this is about. Maybe to disable charging during heavy acceleration ?
- I used to have some small-current (5..6 pin) connector on the alternator (on my cars earlier, at least where I checked). Maybe for the charger-control, or to disable charging at full throttle.
I guess the charger-control is integrated inside the alternator in these audis.
MembersPage/PaulF - Most smart alternators that I have dealt with fail safe to an output voltage of around 13.8V. Usually it is to allow the charging voltage to be lowered at idle to help pullaway. It is also used for feedback to the ECM as to the load on the alternator for torque adjustment.
There is some charging when engine running, 13.7V
- higher than 12.5V means charging
- but less than 14V means the charging current might be low. Most likely the failsafe mode of the alternator.
We'll see how it works.