ChrisLeary
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 posted on 21/7/11 at 09:36 AM |
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Ignition Light Problem
Morning all,
How is everyone today?
I need some advice regarding the ignition light. I'm well and truely a newbie when it comes to electronics.
I picked up an L reg 2.0l zetec powered 7 yesterday, running gsxr throttle bodies and megasquirt.
Now when the key is put into the ignition, you turn it to the on position, and the ignition light iluminates on the dash, as I think it should, then
to start the car there is an aircarft style guarded switch and a starter button. Until the starter gave up the ghost on the journey home yesterday, it
started fine, but the problem is...
...the ignition light flashes on and off pretty much constantly, but particularly when my foot is lifted off the throttle and on low revs.
To me it doesn't seem like a huge problem, but there's obviously an underlying problem somewhere, does anyone have any ideas?
Thanks in advance,
Chris
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RichardK
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| posted on 21/7/11 at 09:54 AM |
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knackered alt, poor connection of lamp wiring to warning lamp, slipping fan/aux belt suppose could cause it too.
Cheers
Rich
Gallery updated 11/01/2011
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Strontium Dog
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| posted on 21/7/11 at 09:59 AM |
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The lamp will illuminate if the output voltage of the alternator drops. Can you put a meter across the battery and see if the alternator is putting
out around 14v. It is likely to be a dodgy alternator or maybe diode pack as the wiring path for the lamp is likely to be sound or the lamp would not
light.
Edit to say: as Richard has mentioned, check the belt! Could be really simple!
[Edited on 21/7/11 by Strontium Dog]
http://s187.photobucket.com/albums/x319/zephyr2000/General%20forum%20uploads/?action=view¤t=3DEngine.mp4
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ChrisLeary
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| posted on 21/7/11 at 10:08 AM |
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Thnaks for the replies, I'll pop down the garage and have a look at the belt tension, I hope its just that! I'll try and get hold of a
fluke to test the output too.
Thanks again,
Chris
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ChrisLeary
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| posted on 21/7/11 at 10:23 AM |
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Just an after thought guys,
I thought the starter had gone, but if the alternator isn't charging properly, would it be correct that the battery would have enough power to
push the starter pin out, I can hear the clunk as it come out, but it wouldn't have enough power to run the actual starter motor?
Thanks,
Chris
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David Jenkins
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| posted on 21/7/11 at 10:29 AM |
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Correct - if the battery is well under par then all you'll get is the solenoid clunking into place.
While you're waiting for a meter, try putting your headlights on then cranking the starter - with a healthy battery the lights will dim a bit.
If the battery's knackered then the lights will probably go out!
Not a scientific test, but it can offer clues...
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ChrisLeary
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| posted on 21/7/11 at 01:40 PM |
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Right, I've just got back from the garage and my findings are...
I think the belt is tensioned ok, I drove from Glasgow to Oxford yesterday and the lights were working fine when the light started to fade, so
I'd assume the alternator is ok. The battery has a self test facility on it, and thats showing green, so I guess the battery is being
charged.
I've checked all of the earths and they were secure, bar one, but I'm not too sure what that was connected to, and because I can't
get it started due to the starter, I'm not sure if it's made a difference!
I checked the wiring to the lamp, to the best of what I could see anyway, and it seemed secure.
I guess I'll have to take it out for another run once I've sorted the started problem and see if anything has changed.
It's just strange that the light is stable when the ignition is first turned on, but then when my foot is lifted off the throttle when driving
it flashes.
I'm a little lost as to where to go with this next.
Chris
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ChrisLeary
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| posted on 27/7/11 at 09:00 AM |
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After some more fault finding, the solenoid on the starter was at fault. So atleast I can start the engine now, but...
... The light still flickers when the engine isn't under load (decelerating). I put the multimeter across the battery and it was reading low,
but when I started the engine the voltage didn't rise to the approx 14v people are suggesting.
Is there another test I can do to check the alternator output or can I already assume the alternator isn't working correctly?
Thanks in advance,
Chris
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