Parasitic draw test

Ask for and share advice on using the PicoScope kit to fix vehicles here.

Parasitic draw test

Postby Neilcur » Mon Mar 11, 2013 3:40 pm

Hi,

Is it normal for the amp reading to go minus 0 when using the amp clamp for this test or am i doing something wrong? i zero'd clamp before i started the capture and had it set on 20a scale

Thanks Neil
Neilcur
Advanced User
Advanced User
 
Posts: 68
Joined: Sun Feb 17, 2013 7:47 pm
Location: South West Scotland

Re: Parasitic draw test

Postby Lee » Mon Mar 11, 2013 4:00 pm

Hi Neil

Have you tried turning the Clamp around, i.e. remove it from the wire, flip it over and place it on the wire again.

it will show positive one way and negative the other.

Kind Regards

Lee :D
Lee
Advanced User
Advanced User
 
Posts: 79
Joined: Fri Feb 19, 2010 10:36 am

Re: Parasitic draw test

Postby Neilcur » Mon Mar 11, 2013 4:14 pm

HI,

When i locked doors the trace went up to top of screen and then settled to 0 then after a short while went minus 2/3 amps so i took it, it was the right way round with the capture going high.

Thanks Neil
Neilcur
Advanced User
Advanced User
 
Posts: 68
Joined: Sun Feb 17, 2013 7:47 pm
Location: South West Scotland

Re: Parasitic draw test

Postby Fat Freddy » Tue Mar 12, 2013 9:23 am

Can you post your file up?

FF
User avatar
Fat Freddy
Zen Master
Zen Master
 
Posts: 267
Joined: Fri May 04, 2012 4:52 am

Re: Parasitic draw test

Postby Neilcur » Tue Mar 12, 2013 11:02 am

I redone the test after posting the question and made sure i had clamp right way round and it was ok and is now reading ok. It must of been something i did? i removed negative lead and put a jumper cable between post and terminal and took reading of the cable. Does the length of jumper cable affect the result or not?
Neilcur
Advanced User
Advanced User
 
Posts: 68
Joined: Sun Feb 17, 2013 7:47 pm
Location: South West Scotland

Re: Parasitic draw test

Postby jez1342 » Tue Mar 12, 2013 6:45 pm

cable length wont effect reading.
if you have to use a smaller thickness wire inbetween battery terminal and clamp make sure you dont interrupt the vehicles power supply as this may hide the fault your testing for :!:
jez1342
User
User
 
Posts: 12
Joined: Thu Jan 19, 2006 6:55 am
Location: weymouth

Re: Parasitic draw test

Postby Autonerdz » Wed Mar 13, 2013 3:43 pm

Neil,

The switch on the amp probe is rather touchy. It's easy to slide it and have it between the range detents and not realize it. This makes it behave very strangely. Make sure you have the slider switch firmly located at the selected range. Also, the battery can be low and not illuminate the low battery indicator but still cause bogus readings.
Tom Roberts
(The Picotologist)
Autonerdz
User avatar
Autonerdz
Zen Master
Zen Master
 
Posts: 272
Joined: Wed Nov 20, 2002 4:19 pm
Location: Washington State USA


Return to Diagnostic discussion

Who is online

Users browsing this forum: No registered users and 0 guests