How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask sean Your Own Question

sean
sean, Ford Technician
Category: Ford
Satisfied Customers: 3105
Experience:  Ford Master Technician.
31670004
Type Your Ford Question Here...
sean is online now

I had a new alternator fitted to my 2001 Mondeo Mk3, petrol

Resolved Question:

I had a new alternator fitted to my 2001 Mondeo Mk3, petrol engine, the battery light stays on. The volts at the battery, engine not running 12.6volts, with engine running 14.7v.
The alternator is delivering the notional correct voltage, but why is the battery light on continuously? Your advice would be appreciated.
Bill Sheils
Submitted: 2 years ago.
Category: Ford
Expert:  sean replied 2 years ago.
Hello, I hope the following assists you.
The charging system on this model is a "smart charge" system where the charge rate is controlled by the engine management (PCM) and it is the PCM that instructs the cluster to illuminate the warning light when a fault is detected.
The most common cause given that a new alternator has been fitted is a smart charge circuit fault.
The small connector on the alternator should have a 12 volt supply at pin 1, this is fed by fuse 30 in the fuse box under the bonnet so check for 12 volts at pin 1 and double check the fuse of it's not there.
If the 12 volt supply is OK then the wiring between the alternator pins 2 and 3 and the PCM pins 72 and 59.
It's not uncommon for the wiring to become damaged then corrode in the engine bay close to the alternator.
If there is a smart charge fault the alternator will revert to a fixed charge rate rather than the charge varying to account for electrical consumers switching on and off.
I hope this helps but if I can provide further information let me know and I'll reply as soon as I'm able to.
Best wishes,
Sean.
sean, Ford Technician
Category: Ford
Satisfied Customers: 3105
Experience: Ford Master Technician.
sean and other Ford Specialists are ready to help you
Customer: replied 2 years ago.

Where is the PCM located.

Bill Sheils.

Expert:  sean replied 2 years ago.
Hello again,
the PCM is located on the right hand side of the engine bay, you'll see the wiring going to it just behind the suspension strut housing, there may be a riveted security shield over the connector.
Let me know if I can assists further.
Best wishes,
Sean.

What Customers are Saying:

 
 
 
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
 
 
 

Meet The Experts:

 
 
 
  • Matt

    Matt

    Mechanical Engineer

    Satisfied Customers:

    191
    BEng hons Mech engineering, in auto industry 22 years
< Previous | Next >
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Mechanical Engineer

    Satisfied Customers:

    191
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/MI/mikeamechanic/2013-4-2_175558_photo.64x64.JPG Mike Kelly's Avatar

    Mike Kelly

    Ford Mechanic

    Satisfied Customers:

    140
    17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.
  • http://ww2.justanswer.com/uploads/FO/fordspec/DSC00877.64x64.JPG fordspec's Avatar

    fordspec

    Ford Technician

    Satisfied Customers:

    11
    ford technician
  • http://ww2.justanswer.com/uploads/AL/allagher/2015-6-23_213635_image.64x64.jpg Gallagher99's Avatar

    Gallagher99

    Senior Vehicle Technician

    Satisfied Customers:

    617
    SVQ LEVEL 3, QAULIFIED FORD SENIOR TECHNICIAN , ATA REGISTERD ,12 YEARS EXPERIENCE
  • http://ww2.justanswer.com/uploads/FO/fordtwo/2014-12-19_163422_arrepair.64x64.jpg Robert's Avatar

    Robert

    Ford Technician

    Satisfied Customers:

    44
    Fully qualified 19+yrs exp/self employed technician in the UK
  • /img/opt/shirt.png Mark's Avatar

    Mark

    Auto Service Technician

    Satisfied Customers:

    59
    Qualified City & Guilds
 
 
 

Related Ford Questions