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1988 Scirocco 16v (Wilda); '02 Passat 1.8T wagon (The Brick); '09 Jetta Sportwagon (wifemobile);
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First off, props on the diagnostic process. :thumbup:
I've found that it's hard to sell people on the voltage-drop method of diagnosing a draw - but, it does work. And, it's a lot less invasive (read: faster and more accurate) than the 'yank the fuses until the draw is gone!'

I'll assume that homework is done correctly, and that fuse 23 does, in fact, provide power to those four things (and nothing else.)
Seasoned master tech (me, not VW - another German brand) says:
This is the point where you unplug control units. Typically, I go in order of 'fastest to access, to longest to access' (because, best use of time in the shop.) But, that's also weighted by 'importance in the vehicle.'
What that means: unplug the quickest-to-get-to thing(s) first, UNLESS said unplugging is likely to cause a vehicle-wide freakout.
Phone module: low/no impact.
Rain/Light sensor: low/no impact.
OBD connector: well, it can't cause a draw (but, no 'insurance dongle' plugged in there, right?)
The J519 module: controls a lot. He gets unplugged last. Plus, I'm not certain as to what all actually goes thru that box - so, being a 'important control unit', there's the possibility of a 'thing connected to it' actually being the cause of the draw (read: not the control unit itself.)

I hope all of that makes sense?
 

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1988 Scirocco 16v (Wilda); '02 Passat 1.8T wagon (The Brick); '09 Jetta Sportwagon (wifemobile);
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4,626 Posts
Oh, 187mA (after the vehicle goes to sleep) is way too high. Normal rest-state power consumption of a car is in the 5-50mA range (depending on the particular car.)
187mA will kill a battery dead in just a couple of days (assuming 100% charged & heathy battery.)
 

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1988 Scirocco 16v (Wilda); '02 Passat 1.8T wagon (The Brick); '09 Jetta Sportwagon (wifemobile);
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4,626 Posts
@cuppie, perhaps you have another suggestion? :)
Yes - actually confirm that it has a draw. Need a clamp-on ammeter that can read low mA DC.

I’d hate to ask the obvious. But....

What’s the health of the battery? Will it Pass a load test?
This, too. A bum battery will do the same thing that you're seeing.
 

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1988 Scirocco 16v (Wilda); '02 Passat 1.8T wagon (The Brick); '09 Jetta Sportwagon (wifemobile);
Joined
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4,626 Posts
20mVAC actually isn't horribly bad - generally, up to 50-100mVAC is acceptable (depending on the car.) The definitive test is with an oscilloscope, so you can see the output waveform.

First, though, check that your DVOM truly blocks DC voltage in the AC ranges (not all do): Set the meter to 20VAC (or closest equivalent), and measure battery voltage (engine NOT running.) Make sure that the meter reads 0.00VAC there.

Because you have that clamp-on ammeter, use it to check the alternator itself for a draw! Just hang it on the alternator output wire - see anything?
 
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