Ford Focus 1.8 Zetec Battery Light Remains On After Alternator Fitted

[Tricky69eng]

Hello people of the Ford Forum,

I have a W reg 1.8 petrol Ford Focus Zetec. I've had it since September and I bought it in a car auction. The car is sound, it passed its MOT earlier this month albeit with a new brake cylinder on the o/s/r brake, but I cannot crumble as the car was cheap.

My problem is that my alternator packed up the other day, it didn't give me any warning. The radio turned off, then the dash board lights started going. Not at any point did the battery light or any light other than the air bag warning light come on to give me notice.

After calling out the AA I was told it was the alternator. So after buying a battery charger and charging the battery completely full I drove it with no heater, lights and radio to my local motor mechanic 20 miles from where I live.

They have replaced the alternator but now the battery light stays on and the front windscreen heater does not work. The garage say they will sort it, but as I needed the car back I have to take it back when its convenient.

I just wanted to know everybody's thoughts? Is it the alternator, a loose wire, what could it be? I'd appreciate any feed back so I can seem smart when I go back to the garage and tell them to investigate further.

[jeebowhite]

It could be as simple as a loose wire, but the fact the heated screens wont work shows its likely to be something on that circuit (so your looking in the right place!)

whats the voltage output across the battery with engine off and engine on?

[Tricky69eng]

Hi

14.4 volts I'm sure I heard the mechanic say.

[jeebowhite]

If that's the case the smart charge is working correctly with the alternator so it sounds like a potential battery issue?

[Tricky69eng]

Really, you saying try a different battery? Can a duff battery really make the front heater not work & the battery light stay on? I charged it fully.

[jeebowhite]

It's not all about battery charge but amps and cell strength. How old is the battery?

[Tricky69eng]

That I am afraid I can't say as I don't know. :( But thanks it's worth checking out.

[jeebowhite]

It sounds to me the battery is failing to charge properly probably a warped cell. Not sure where your based as I'm on the mobile, but you should look to either borrow a battery or just replace it. Get a Bosch s4 or similar and keep that battery, then when you get rid of the car keep the new battery and chuck the old one in then use the new battery in your new car