transit connect over charging?

The charge light on a smart charge system like a transit connect doesn't come directly from alternator, it feed comes from pcm (
engine ecu) , it doesn't excite like conventional systems, pcm control the amount of charge , via blue grey wires red wire is 10amp fuse link given battery voltage reference. If you unplugged three wires alternator will charge it's nuts off when revs applied , fault usually with short wiring from alternator to radiator or under battery tray to fuse box. If you can find broke wires ect you need someone with a scope to test further.

Busted knuckles
January 2017

Same problem I changed the alternator for a new one, but light still comes on. I've checked wiring comin from the alternator and looks like someone has been there b4, but no breakages in the wiring and none of the fuses blown????

Josh
April 2013

Hi,

The transit connect is fitted with ford's smart charging
Alternator, Controled by the engines ecu. It has 3 control wires connected To the multi plug on the alternator (Grey Blue and Red). The grey and blue are Data wires connect directly to the ECU, The Red wire
is a voltage reference connected from the alternator regulator to f10 of the engine bay fuse box. A blown f10 fuse or poor connection on this wire will lead to a higher voltage than required for normal charging (as high as 16-17volts) and will bring on the battery fault light)
The grey wire is the alternator request which has a digital square wave output from the ecu. This controls
the output of the alternator. The blue wire is the feed
back to the ecu (square wave) and tells the computer that the alternator regulator is doing what it says.

Proper diagnosis, really needs a scope or scantool
capable of displaying the signals on the data wires from the ecu to the alternator.

Hope this helps

Brightspark
March 2010

Check wiring from alternator these vans have a habit of breaking wiring within 18 inches from alternator

Andy k
February 2010

Hi,

I think this is most likely the brushes in the alternater worn out and it has stopped charging. the reason for the flashing is possibly that the brushes were at the end of their life and connecting sometimes.

rick
February 2010

hi yes had this before its the regulator in the alternator changing alternator will fix this problem

martin
January 2010

I have no qualifications or experience but the alternator in some vehicles, for it to work correctly, needs the charging light to be working. The charging light bulb will be easier and cheaper to replace than the alternator so it's worth a try for a few bob....

Wikipedia says this...

"Once the engine is running and the alternator is generating, a diode feeds the field current from the alternator main output, thus equalizing the voltage across the warning light which goes out. The wire supplying the field current is often referred to as the "exciter" wire.

The drawback of this arrangement is that if the warning light fails or the "exciter" wire is disconnected, no excitation current reaches the alternator field windings and so the alternator, due to low residual magnetism in the rotor will not generate any power."

Good luck...

Peccavi
January 2010