Parasitic battery drain - or not?

[Kaldek]

Howdy folks,

Being an electrickery guy, I decided to measure the parasitic battery drain on my 2000 model Legnum. I was shocked to get a reading of 300 milliamps. Way too high, I thought.

So then I disconnected the negative battery terminal, but I am still seeing a 300 milliamp current on the main wire to the starter motor - on an open circuit!. With the battery connected and checking the black/white wire that leads to the rest of the car, I only see a 30mA draw, which is what I'd expect.

I'm using a quality clamp-style current meter hooked up to my multimeter which is zeroed before use each time, so it's not my metering gear. So, is this some form of weird induction in the wire due to it being heavy gauge or something?

 

[sideburns]

I'm an auto electrician so I check these kinds of things quiet often the easiest way to check it is use a multimeter remove the positive terminal and put one probe on the battery stud abs the other on the removed terminal with it on amps.
You may need to lock the car and leave it a few min till it all settles then you can get a reading just make sure all doors etc are closed
The specs are 5% of reference voltage so it should be 0.6 amp

I hope this helps you out

 

[Kaldek]

Yeah, inline multimeter is probably a good idea. Hadn't thought of backing up the current clamp with an inline test.

 

[TME_Steve]

0.6a would still be a lot I would have thought. Pretty sure I've seen 40mA ish on vr4s

 

[sideburns]

Sorry 0.06 amp left out the other 0
that's the max drain on a 12v system any more causes a flat battery in less than 2 weeks

when checking a new car you have to let it sit falcons take 30 min before the computers go into a sleep mode and stop draining

 

[slickd1]

Chasing flat battery demons myself. My dash cam that turns on when it senses shock was drawing 600ma, then dropping to 170ma after settling. Found a really badly corroded fuse running to it.

Inline multimeter sees 0.02-0.03ma instead of 0.190 when the cam is connected.

And that's with a voltage regulator in the grille that constantly displays voltage on an LCD screen. Draw should be even lower than that on a stock vr4 without an after market alarm. Also, check your alarm, as they're often always awake.