Ford Fiesta Alternator / battery

[pclayto]

I have a 1994 Ford Fiesta 1.1 LX.

The battery went dead, and after charging it, I did a voltage test across the terminals while the engine was running and being revved. I only got 12V, so I believe that the battery is not charging.

I think this means that the alternator is not working properly.

I also noticed that the battery is 7 years old which I believe is old for a car battery. Would a dodgy battery cause a loss in charging voltage?

also when I drive the car (with the battery not being charged), I can't get the rev counter to go over 2000 revs nor the temp gauge to move, although my speed is not restricted.

I just want to be sure this is an alternator problem before buying one (2nd hand).

Thanks, Paul

 

[libby lou lou]

Any car bar will be happy to do a bat/alt test free of charge, in the hope of making a sale to you, so your'e gauranteed a positive result.

 

[wotan]

I have a 1994 Ford Fiesta 1.1 LX.

The battery went dead, and after charging it, I did a voltage test across the terminals while the engine was running and being revved. I only got 12V, so I believe that the battery is not charging.

I think this means that the alternator is not working properly.

I also noticed that the battery is 7 years old which I believe is old for a car battery. Would a dodgy battery cause a loss in charging voltage?

also when I drive the car (with the battery not being charged), I can't get the rev counter to go over 2000 revs nor the temp gauge to move, although my speed is not restricted.

I just want to be sure this is an alternator problem before buying one (2nd hand).

Thanks, Paul

Alternator faulty without a shadow of doubt, rev counter not working correctly classic sympton + low voltage being measured when engine revved up.
Seven years is quite a good age for a battery, it's reached the end of it's useful life.

Wotan

 

[davieboy]

check the voltage on the battery terminal on the back of the alternator.

also check for +12v on the small terminal on the back of the alternator.

broken main wire from alternator to battery (sometimes via starter) is not uncommon on these.

 

[pclayto]

thanks all. I unplugged the lead from the alternator that connects the alternator and the battery.

On the alternator are three male pins. I put a volt meter probe on these and connected the other probe to ground while the engine was running. I could not get a voltage reading at all.

New alternator time I think. And I might get a new battery while I am at it.

 

[Spark123]

Not 100% sure - you are not meant to run an alternator without it connected to a battery
A lot of alternators need to have 12v applied to them before they will deliver a charge - sometimes this is only a small current via the small alternator indicator lamp on the dash. I'm thinking unplugging all the connections will mean no excitation voltage to the alternator and hence no 14v ish back from it.

 

[pclayto]

So I got a 2nd hand alternator and I have fitted it (the original alternator was stamped 1991, the 2nd hand one is 1995).

Car seems to work fine now. Rev counter works again and there is over 13.5V at the battery terminals when the engine is running.

However the battery warning light on the dash comes on whenever I the engine is running. the electrics are working fine though and I have done 20 miles with the warning light on and nothing has gone wrong.

I plan on replacing the battery tomorrow, as its about time anyway. I hope this solves the warning light issue.

 

[Thomas199]

hi pclayto
did a new battery fix your charge light???