2007 Fiesta - Loss of electrics when driving now wont start

[souldriver]

Recently son was out driving his '07 Fiesta and he suddenly lost power to headlights, radio and heater (not fully – lights dimming then coming back on type thing). At same time battery warning light and possibly other warning lights (he’s not sure) came on. Engine kept running ok but once home it wouldn’t start again but started with a jump start with booster cables. Took battery out and charged it. When battery back in everything seemed fine – started first time and no warning lights. Took for a drive for same thing to happen again – although this time the ABS warning light came on as well as battery light. Happened after he had braked sharply. Again wouldn’t start again after getting home. Replaced battery with a new one and seemed ok but happened again a few days later. This has happened right when he was hoping to trade in/sell the Fiesta (£500-800 at best) so not sure if worth major expense.

Any help appreciated.

[Camelot1971]

Almost certainly the alternator - bad charging a low battery will cause all sorts of fun with warning lights. No idea on cost to fix - was around £300 at Ford for a similar age Mondeo that needed a new alternator too. I'd expect an indie garage would be cheaper.

[ACB85]

My old Mk1 Focus was the extreme of this. Motorway bound and the battery light came on. Then very quickly it died. Battery swap to get it going to a safer place. Then same thing again. Realised the root cause.

I wouldn't keep doing the battery swapping. My saga of flat batteries resulted in the the sensor in the gearbox for speed being shot. Never the same again.

Bear in mind an indy might stretch the auxiliary belt to squeeze the new alternator in. Screw up the tensioners. Then require a revisit for horrible squeaking belts. Be sure they do a proper job. Speaking from the same Focus Mk1 experience ;-)

[souldriver]

Thanks for the replies.
I read on a different forum that to test the alternator you can turn on all lights, heater etc and then rev the engine and see if headlights get brighter. And if so, then the alternator is ok. I did that after putting the new battery in and they did brighten. Is this maybe not that accurate and it could still be the alternator? Others thought it might be a loose earth point too?

[TooLateForAName]

Main earth strap?

[souldriver]

TooLateForAName said:

Main earth strap?

This has been mentioned. Excuse my ignorance, but I'm a complete novice. Where would I find that to check it?

[TooLateForAName]

souldriver said:

This has been mentioned. Excuse my ignorance, but I'm a complete novice. Where would I find that to check it?

Sorry, I've no idea where anything is on a fiesta might vary depending on the engine. There could be several. Typically from the chassis to the engine/gearbox or to the alternator.

[carinaman]

Would getting a multi meter and measuring the resistance between the negative battery terminal and some bare metal on the body check the earth strap?

Using Google to search I found that:

https://www.justanswer.co.uk/ford/80lbf-fiesta-zet...


It mentions a Technical Service Bulletin and a little pop up appears asking what is wrong with your Ford.

[souldriver]

TooLateForAName said:

Sorry, I've no idea where anything is on a fiesta might vary depending on the engine. There could be several. Typically from the chassis to the engine/gearbox or to the alternator.

Thanks I'll have a look.

[souldriver]

carinaman said:

Would getting a multi meter and measuring the resistance between the negative battery terminal and some bare metal on the body check the earth strap?

Using Google to search I found that:

https://www.justanswer.co.uk/ford/80lbf-fiesta-zet...


It mentions a Technical Service Bulletin and a little pop up appears asking what is wrong with your Ford.

Thanks, there's a bit info there that should help. I went on the pop up as well but you need to sign up and pay a fee to get an answer so gave up on that.