pekwah1
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| posted on 13/7/14 at 09:45 PM |
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Alternator not providing enough voltage
Hi guys,
Running a 2.0 blacktop zetec on standard ignition with stock ECU and alternator.
For some reason, I'm only getting around 13 volts when running, and if I've got the lights and rad fan running, it drops below 12v.
I don't have anything significant on my car to draw a lot of power, any ideas why I might not be seeing what I should?
Regards
ANdy
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Smoking Frog
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| posted on 13/7/14 at 09:59 PM |
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Well if I had to guess I'd say alternator, but only if the battery is OK. Here's a link which may narrow it down.
http://www.w8ji.com/battery_and_charging_system.htm
I had a similar problem turned out to be a faulty test meter. Worth checking as it could have saved me from replacing mine.
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pekwah1
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| posted on 13/7/14 at 10:09 PM |
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Nice one, that looks pretty helpful, ill run through the tests it talks about...
If it makes any difference I have a gel battery (varley redtop 25)
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britishtrident
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| posted on 13/7/14 at 10:15 PM |
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If you are using a DMM check the PP9 battery in the DMM as they give false readings if the battery is low.
The car battery should have at least 3/4 charge (ie 12.5 volts with everything switched off) before you test.
If the above is OK it looks like a knackered alternator.
[Edited on 13/7/14 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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jeffw
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| posted on 14/7/14 at 07:19 AM |
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I assume your alternator light is on when the engine is off and off when the engine is running? Is the alternator light a normal lamp or a LED. It
sounds possible like the alternator is not being excited...
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BaileyPerformance
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| posted on 14/7/14 at 11:09 AM |
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The standard Focus alternator (black top only) is electronically managed from the Ford ECU via CAN Bus.
Have you got the alternator connected correctly to the Ford ECU? (2 pin plug)
The + wire from the alternator to the starter / battery + needs to be 6mm2 minimum. Make sure its well earthed to the block too.
We have seen odd voltages at the battery on a standard focus - Ford's "intelligent charging system" as high as 15v and as low as
13v
Unplug the 2 pin plug from the alternator, this will force it into default output of 14v, if still 13v at battery check at the alternator, if still
low the alternator is faulty.
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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pekwah1
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| posted on 14/7/14 at 05:18 PM |
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Right,
12.5v disconnected
14.2v when running above idle (holds nicely with extra electrics turned on)
13v(ish) when I turn the engine off.
All sounds pretty good to me, looks like my dash is having a paddy!
Cheers for the help guys.
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