Skip to content
View in the app

A better way to browse. Learn more.

Ford Owners Club - Ford Forums

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.



Join the Independent Ford Owners' Club

Our community has been built by enthusiasts, for enthusiasts, and proudly run by Ford owners' for over 18 years. As an independent, non-official club, everything you’ll find here, advice, support, and opinions, comes directly from members with genuine Ford ownership experience.

Join our friendly community... it's Free!

 

Battery warning light

Featured Replies

Hello,

I have a problem with my Ford Mondeo 2002 2Litre TDDI, The alternator in the vehicle failed and a brand new one bought from the Dealer was fitted by an electrician. Although the new alternator is charging and the car is running sound, I have the battery warning light that comes on about 20 seconds after I start the engine. I also noticed that when this light is on, the front heated windscreen doesn’t light up and function.

Almost 2 years ago, a new alternator was fitted in my car and I had same problem (I am a night time taxi driver therefore the alternator keeps failing due to electric surcharge). I took the car to the dealer and they found a fault in the wiring loom.....I was charged £245.

Any suggestion what this wiring loom can be?? any help will be very appreciated



Hello,

I have a problem with my Ford Mondeo 2002 2Litre TDDI, The alternator in the vehicle failed and a brand new one bought from the Dealer was fitted by an electrician. Although the new alternator is charging and the car is running sound, I have the battery warning light that comes on about 20 seconds after I start the engine. I also noticed that when this light is on, the front heated windscreen doesn’t light up and function.

Almost 2 years ago, a new alternator was fitted in my car and I had same problem (I am a night time taxi driver therefore the alternator keeps failing due to electric surcharge). I took the car to the dealer and they found a fault in the wiring loom.....I was charged £245.

Any suggestion what this wiring loom can be?? any help will be very appreciated

hi i have a focus st170 and mine is doing the same as yours - changed alternator and light is still on. i have had a few people message me back with -a bad earth in the car? dodgy alternator and battery well mine is none of those. my car is in the garage at the moment to see if they can find the problem so ill let you know.

Hello,

I have a problem with my Ford Mondeo 2002 2Litre TDDI, The alternator in the vehicle failed and a brand new one bought from the Dealer was fitted by an electrician. Although the new alternator is charging and the car is running sound, I have the battery warning light that comes on about 20 seconds after I start the engine. I also noticed that when this light is on, the front heated windscreen doesn’t light up and function.

Almost 2 years ago, a new alternator was fitted in my car and I had same problem (I am a night time taxi driver therefore the alternator keeps failing due to electric surcharge). I took the car to the dealer and they found a fault in the wiring loom.....I was charged £245.

Any suggestion what this wiring loom can be?? any help will be very appreciated

hi i have a focus st170 and mine is doing the same as yours - changed alternator and light is still on. i have had a few people message me back with -a bad earth in the car? dodgy alternator and battery well mine is none of those. my car is in the garage at the moment to see if they can find the problem so ill let you know.

  • Author

OK, let me know

  • 1 month later...

Hi there

I've had this problem for a while now since my alternator failed(?)

My mechanic fitted a new alternator and the light stayed on although the battery was charging ok.

He then removed the new alternator and had it tested...all ok...light still on though.

He then thought possibly a fault with the lead connecting alternator to loom. Apparently ford dont supply this on its own, has to be with the complete loom..because there's a common fault with them.

So got a 2nd hand lead from scrapper, fitted but still the light is on.

that's where I am at...now thinking of trying to get another lead to try.

Have any of you got any further forward?

thanks

the three pin plug to the alternator are known to give trouble check that all the connections are ok, the light remaining on could indicate a fault in the smart charge system do a search for ford smartcharge and read all about it.

i'm picking up another lead tomorrow to try.

If it is a fault with the smart charge system how do I get it rectified...will it be a ford job do you think?

can also be the live cable from alternator to battery +

if this has a break it can put light on

steve

www.sr-performance.co.uk

  • 3 weeks later...

Hi, my son also had the same problem last year with his 1.6 T reg focus, namely the battery warning light would come on about 15 seconds after starting, even though the alternator was changed and was charging ok.

At first we thought it was the dreaded focus instrument cluster problem.

We finally traced the fault to a break in the small red wire from the alternator 3 pin plug to the under bonnet fuse box.

I dont know if the wiring is similar on a Mondeo but its worth checking all wires to the alternator with a multimeter for voltages, earths, and continuity.

John

Latest Deals

Ford UK Shop for genuine Ford parts & accessories

Disclaimer: As the club is an eBay Partner, The club may be compensated if you make a purchase via the club

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

The "Digestive"






Background Picker
Customize Layout

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.