Hello.

I suspect that I will soon need a new alternator. Just this week while driving, the battery light can on for just a minute initially. However since then it now comes on and off (seems to come on more while driving on A roads).

I tested the battery voltage (engine off) after the car had sat overnight and it was 12.4V (is this low?). I then retested with the engine running and it was between 14.2V-14.3V.

There are no rattling sounds from the timing belt area (belt was changed in 2018) and I've experienced no power loss and no engine management lights, so am guessing that the alternator has an intermittent issue.

I would like to get a replacement but have realised that there are 4 different types, 80a, 105a, 120a and 150a.

Which rating would I need please? I would appreciate some advice.

 
Thank you,

 

Sean

Hi Sean,

Be aware, I'm not a mechanic and I know very little about cars but I also have a 2006 Mk2 focus, 1.6 Tivct, and last year I needed the alternator replaced. The mechanic said it was 105 amps. Hope this helps.

Mazio

Hi Mazio,

ah that is great just what I needed to know. Thanks alot :)

A word of caution, your car might or might not use the same alternator.

The size is determined by the trim level of the vehicle and importantly what extras it has. For example heated seats, or heated windscreen, or the type of headlights.

The only way to be 100% sure is to remove the old alternator and read the model plate which will have the make and type of alternator.

Hi Sean and Unofix,

I'd like to confirm Unofix's comment. The mechanic did ask me questions like that, if I had heated seats, how much electronics I would be using and if I would be blasting super loud sounds all the time. I should have mentioned that. My car has the Sony stereo, parking sensors and the climate pack, and I did see the old alternator which said 105 amps on the label.

Hope all goes well.

Ahhh, ok. That is really good to know. 

Mine is an LX trim. I'll try to remove the alternator today and take a photo of the label.

 

Thanks so much Unofix and Mazio.