Focus Fanatics Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I know very little about car mechanics so i hope someone can help.
I have recently purchased a 2002 focus 1.8 CL TD (02).
Ther battery warning light stays on when the engine is running and my local garage told me that the alternator needs replacing at a cost of £250.
I have been driving the car regular for the past 3 weeks and there seems to be no power loss in the battery whatsoever. I thought that if the alternator needed replacing then the battery would not be charging thus draining power from the battery.
Could there be another explaination?
 

·
Registered
Joined
·
8,262 Posts
Its probably a case of the alternator is on its way out, and the computer is noticing enough of a voltage drop to trip the light yet the alternator is still putting out enough power to run the car.

That said, I'd check all the wiring connections going into the alternator. I had a similar problem and it turned out it was one of the sensor wires had come off, and if I pushed the wire back together the light would turn off and the engine would go from a rough idle to a smooth one.
 

·
Registered
Joined
·
3,737 Posts
I agree. My first step would be to check and clean the electrical connections to the alternator and the battery. I would also check the grounds in the engine compartment. If one had a voltmeter, checking the battery voltage at rest and then while the engine is running would also be useful.

It would be interesting to know if the battery light goes out if the engine is rev'ed to a high RPM. Often if an alternator is getting "weak" due to a short in the winding or something, higher RPM will make the light go out.

In the old days, a slipping belt could also be the cause; however, since the advent of belt tensioners and serpentine belts I have never seen belt slippage sufficient to cause a charging problem.
 

·
Registered
Joined
·
1 Posts
I have had to replace my alternator on my 2000 ford focus TWICE in the past 2 1/2 years! Everything your car is doing is what mine would. Battery light stayed on, but my car never died. It was at least a month before my car finally started dieing whenever in idle.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #5
After trying all your suggestions i have finally had the alternator changed,
The light has finally gone out.
Thanks for all your helpfull suggestions.
 
1 - 5 of 5 Posts
Top