Ignition light on when engine is running

[T Burg]

Hi everyone as anyone had a problem where the engine is running with the ignition light on but still charging 

[F0CUE]

You might need a new battery . 

 

[isetta]

how have you verified it is still charging.

Focus 1.8tdci has a massive battery that can keep going for quite a while after the alternator has failed. 

have you put a voltmeter on it

[isetta]

hope you don't need an alternator. I changed it on my brother's 2008 focus 1.8tdci a few weeks ago and it was a long old job

[T Burg]

Thanks for your replies guys.

Yeah I put a battery and alternator tester on, it works on a light system when the engine is off it shows battery is fully charged a engine running it shows charging ok (the 3 charging lights are 1 ok. 2 maximum charge. 3 overcharging.)

[T Burg]

Hi isetta.

When you changed the alternator did you do it easy enough by jacking up the car or did you have to use ramps. 

[isetta]

I jacked it up front right and put an axle stand under for safety. I do have a trolley jack , not sure how high the standard jack would get it. Standard jacks are a bit flimsy in my view . I wouldnt want to lay under it just relying on a jack of any type. If you do this job you will find There are plenty of bolts with restricted access to annoy you

[isetta]

Not used any tester with lights on before. I would prefer a proper voltmeter. Another rough test. In the dark, start engine, put everything electrical on, as much as possible. Have it on tickover, now increase revs a tad, do headlights go brighter, that would prove the alternator is doing something ,

[T Burg]

Thanks for that I was going to do that last night but only with my head lights on against the wall but forgot but thanks for that that's a better idea with everything else on as well, I'll try it tonight I did just try the head lights against the garage door just now but it's too light to see well enough. 

Thanks I'll let you know how I get on 

[isetta]

Ideally you want the tickover to be low which might not happen if the engine is not warmed up. You could drag the tickover down by : handbrake on HARD . Start engine, foot on clutch , put in top gear, lift foot off clutch slightly and carefully to cause clutch drag to bring engine speed down, the headlights dim a bit?  But don’t drive into your garage door! And don’t burn out the clutch