Battery light on after replacing timing belt

2011 FORD FIESTA
55,000 MILES • 1.6L • 4 CYL • 2WD • MANUAL
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GAI MCGRATH
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I had timing belt changed and the battery light is staying on. My mechanic said the battery and alternator are charging fine. He had an elect look at it and he cannot find the reason. When they put the code reader on there is no code coming up.
Nov 13, 2018 at 4:11 AM
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ASEMASTER6371
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Good morning.

If the alternator is charging correctly, it could still be the alternator. It contains diodes inside and if one fails the light will come on but it can also charge at the same time.

If you have a voltmeter, put it on the battery with the engine running and check the voltage. It should be 14 to 14.5 volts. Then switch the range to AC volts and see if there is any reading. That will tell you if there is a failed diode.

Roy
Nov 13, 2018 at 4:28 AM
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GAI MCGRATH
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Thanks Roy, the mechanic took it to a auto electrician and he tested it himself and said it all tested fine and he is puzzled.
They said to drive it for a week and see what happens.
My concern is the light was not on when I dropped it there before they changed the timing belt.
I have now I have been driving it for one week and still not off.
I had the alternator replaced in it 18 months ago with a genuine Ford alternator.
Nov 13, 2018 at 5:01 AM
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ASEMASTER6371
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I understand but something is wrong. Just driving it to see what happens is not a professional answer from a shop that performed a repair that has ended in a problem.

You need to be more forceful and return it to them and tell them to return it to you in the same condition you presented it to them. Something happened during the repair.

My guess is that they did not remove the battery cable during the repair and something arced during the repair that triggered the light.

Your last resort is taking to someone else and have a diagnostic done to find the issue. Then either have the original shop perform the repair or pay the second shop for the repair.

Roy
Nov 13, 2018 at 5:08 AM
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GAI MCGRATH
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You are right, I think I will get a second opinion and see where that goes.
Thanks for your help.
Nov 13, 2018 at 6:50 AM
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ASEMASTER6371
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You are welcome.

We are always glad to help.

Roy
Nov 13, 2018 at 6:53 AM