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 Matt Your Own Question

Matt
Matt, Mechanical Engineer
Category: Ford
Satisfied Customers: 21075
Experience:  BEng hons Mech engineering, in auto industry 22 years
12772297
Type Your Ford Question Here...
Matt is online now

RA-ml

Customer Question

Hi - I have a 2.5T Mondeo. A few times now, what appeared to be a flat battery? Jumped started the car via cables - all ok. This am - the same but now the dash lights are going mad, the car jumps when I accelerate and the central console appears to be affected - generally the electrics. Could this be the alternator?
Submitted: 4 years ago.
Category: Ford
Expert:  Matt replied 4 years ago.
Hello

a flat battery will give all sorts of odd effects so 1st check that the alternator is actually charging the battery in the car by taking a battery voltage reading with the engine off then another with the engine running. The 2nd reading should be higher than the 1st and climbing steadily. And also check that the alternator is secure to the engine as this provides the ground for the charging circuit and make sure that the engine / gearbox earth strap is secure and the contacts are clean and bright. if the alternator appears not to be working - take it to a electrical specialist and ask them to test it as sometimes you can replace just the diode pack and this will repair the alternator without requiring replacement



Also how old is the battery? – As even good quality ones need replacing every 5 years and faulty battery just won’t hold a charge


if this is OK I'd check the current drain aspect, the best way to find what circuit is causing the excessive currant drain is to fit a current sensing multimeter in series with the positive battery lead on the car and the battery, or use a current clamp meter on the battery positive cable.

A typical current drain with everything off and un-alarmed should be around 0.05Amp and if its higher than this remove a fuse and re-measure, if measurement doesn't change then replace the fuse and remove the next. Once you've isolated the circuit with the excessive drain check the wiring connections and plugs to components and the wiring harness that runs by the engine bay fuse box - the wiring harness chaffs / rubs through and gets damaged - but its not always easy to see so be careful when checking..

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:

    190
    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:

    190
    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:

    587
    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:

    43
    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