Power Draw? From where?

helidiesel

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Incorrect... A good amp clamp (Like a Midtronics) will pick up a parasitic draw easily. 50mA is what's usually considered max for "normal draw" and an amp clamp will get you within 10-20mA of an inline meter at that range.



Put your hand on the alternator with the truck off. If it is hot replace it as it is drawing your batteries down. There is a test you can do with it running for that but I forget how to do it. It may charge "fine" while still having this problem though so keep that in mind...

If it's not the alternator drawing them down and you're sure you have a parasitic draw go into the fuse box and check for a voltage drop across fuse pins (The nubs on the back). If there is current flowing through the fuse there will be a slight voltage drop across it.

But before doing any of this test your batteries!


Ok but now you are putting the clamp on every wire to find the load. It's ez to determine if there is a draw but can be difficult to locate it. That's why the voltage drop of the fuses is the best troubleshooting for this situation IMHO.
 

laserjock

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Putting the amp clamp on and pulling the fuses and relays one at a time will do the same thing. If you break the circuit, the draw should go away. You don't put it on every wire.
 

icanfixall

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I agree with the above. The amp clamp on a bundle of wires shows where the leak is but not the wire thats leaking. Gotta search each wire in the bundle but at least you have the bundle found.
 

franklin2

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If you have a amp clamp that will read DC, good for you. I haven't looked lately but I remember years ago those things where expensive. Maybe they have come down in price.

I finally found the article in that link/magazine, that's a interesting way to do it, but no thanks. The testlight is a very simple way to do it, and it's a very simple thing for someone to do who knows little about electricity and doesn't like messing with wires, and does not even have a good DVOM. A lot of people are afraid of wiring and know nothing about the circuits and how they work, the testlight method is very simple for them to do and get results. That's why I recommend it.
 

Greg5OH

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i was pulling .4 of an amop just sitting there. unplugged all fuses, same thing, tried a known good regulator same thing. Alternator wasnt magnetized.
Took it off, brought it in. tested "good" the guy said it was makign a weird noise (duno never heard anythign strange) but he gave me a new one anyway. look at that, no more power draw, truck started fine this morning.
 

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