Parasitic ELectr. Load - 06 E350 ?
 

Hi Gang, I noticed my battery seemed to discharge pretty quickly over 2-4 days or so. So I thought I'd try a method for finding shorts I had been told was simple and reliable. It seems logical at least.
I disconnected my Neg. Cable and out a Test Light between the cable clamp and the neg. post. The light completed the circuit and the light lit. I hoped I could pull fuses one after another thinking the Test Light would go out when I got to the right one/circuit.
I checked each fuse next to the steering wheel, then then did the same for the fuses in the engine compartment. Unfortunately, the light bulb never wend out!
Now I'm wondering if there is a constant Parasitic Load on the battery? I know there are a number of computers but I thought if the car was turned off, the parasitic lost would be nil. This doesn't seem accurate though -
Is there a better way to test for a short? Please be specific, electrical stuff is not my strong suite. ;-)
Thanks ya'll --

The next thing to do is disconnect the alternator B+ wire. This could indicate a shorted alternator diode.

Quicker way. Hold a piece of steel ( like a screw driver ) against the alternator pulley or back of the alternator, if it sticks the field is staying on or there is a shorted diode for the stator. Actual shorted not what some call any electrical fault.

97 sl320 cool man

Order an inductive amp meter from amazon to measure milliamps, car should be at rest at 37 tO 70 MAXIMUM, start with front sam feed , then rear sam then interior, in the trunk you will see next to the spare agaist the sheet metal 4 single10 gauge wires that feed car sams , test each of 4 legs , onceif you find the excessive draw try the fuses first , but after you remove each fuse and plug it back you must wait for "CAN"BUS to go to sleep,or take it to the dealer, they can connect to the bus and see which control unit is on for further diag, usual culprits are radio,teleaid if you have it , switches near upholder (when drinks spilled) etc

Parasitic Load
 

About how long should I wait to be sure the CAN has gone to sleep?

I can get an inductive device to attach to my DMM, but which wires should I be testing?

Thanks for your suggestions!

Sincerely,

Parasitic Load
 

Would I still be looking for the test light to go out; like when I tested the fuses?

Thanks!

Parasitic Load
 

Thanks! I'll do this today! (love these kinds of quick tests!)

If you get an inductive amp meter, be sure it measures DC as the lower end ones only measure AC. Extech and Tenma made decent general use test equipment.
Be sure to get one with small tongs as industrial level meters are too big for most automotive use.

$ 50 for a lower end but still useful DC clamp ( on sale from $ 100 )
https://www.newark.com/tenma/72-9480/digital-multimeter-clamp/dp/76T4530


When using a general use amp clamp, the last few miliamps can be difficult to chase due to the meter floating around.

start at battery , then start with sams , 10gauge leads,etc , recently I found it was a cluster on a w 211fuse 64, start with basics fuses first , your going to need wiring diagrams

Parasitic Load
 

So after I disconnect the B+ wire, what do I measure that could indicate a shorted diode?

Thanks!

, I think he means disconnect and see if your current draw is gone

Test the same way you did before.

OK, Thanks! (Sorry, I'm a little lost when t'shooting electrical/electronics)

Sincerely -

Parasitic Load
 

Thanks! (duh!)