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Message started by liteace on Mar 27th, 2012 at 12:15pm

Title: Alternator ripple \ diode test
Post by liteace on Mar 27th, 2012 at 12:15pm
Hi All, Just having a play today, plugged Pico into me 26 year old work van that has original alternator, done an Alternator ripple diode test, it all looks good, I was quite surprised seeing as it's 26 years old. Can someone have a look at the saved wave for me, have a look at screen 1 to 12, they are cooling fan on and just at the beginning of 12 to 15 is fan switching off, on 1 to 12 is that just noise from the cooling fan motor, if i activate filtering it goes ?

Thanks
https://yabb.autonerdz.com/cgi/yabb2//YaBB.pl?action=downloadfile;file=liteace_fan_on_off.psdata (6667 KB | )

Title: Re: Alternator ripple \ diode test
Post by drdiesel1 on Mar 27th, 2012 at 10:44pm
It's good that you noticed the coolant fan and attributed the noise to it.  Whenever you have abnormal noise, always double check the ground too  [smiley=2cents.gif]
Ripple_002.jpg (105 KB | )

Title: Re: Alternator ripple \ diode test
Post by liteace on Mar 27th, 2012 at 11:38pm
Thanks, that's exactly where it shuts off, its not a factory fitted fan its a used one off another make of vehicle, its been there a couple of years now and does its job quite well, the earth for it is direct to battery, would you say this was abnormal noise or just the norm for an electric fan ?

Thanks

Title: Re: Alternator ripple \ diode test
Post by drdiesel1 on Mar 27th, 2012 at 11:45pm

liteace wrote on Mar 27th, 2012 at 11:38pm:
Thanks, that's exactly where it shuts off, its not a factory fitted fan its a used one off another make of vehicle, its been there a couple of years now and does its job quite well, the earth for it is direct to battery, would you say this was abnormal noise or just the norm for an electric fan ?

Thanks



I've never really measured noise relationship with fans, but it's very possible it's normal as long as the connections are good. 
Having it grounded straight to the battery could be why it's so pronounced in your WF.

Title: Re: Alternator ripple \ diode test
Post by liteace on Mar 27th, 2012 at 11:58pm
Thanks again for the info, i'll check another one today thats got a fatory fitted fan and see what its like. Its 9am here, im off to work now

Thanks

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