Alternator Wiring

[Guest chris.childs]

Does anyone know how to wire a Magnetti Marelli 80A Zetec SE alternator up (its also used on the Focus Zetec E engines, not sure if its the same as the mondeo etc though?) seems to have 4 wires coming out of it!

One is the main charging lead that does straight to the battery, but the other three seem to go to the ECU. Does any one know what each of these are/do and how to connect them up?

 

Chris

[Guest Ant]

At a guess they're used by the ECU to monitor the alternator, and possibly to switch the charging onn and off. Some newer alternators are "smart" and can be switched on and off by the ECU - basically to imporve performance. The idea is to charge the battery at steady state running conditions, but switch off the charging when you put your foot down to overtake something.

 

I'm not sure if this particular alternator does that or not. A haynes book to a car with this alternator fitted may tell you what its about. Failing that an auto-electrics centre may help you out.

 

Ant