This is all good info EXCEPT: These new cars always draw a tiny current to keep the computers alive. But more than that, when power is first connected (after being disconnected) the computers run through some kind of power-on diagnostics that consume significant (less than an amp) current. You need to wait until the computers go back to sleep to see if there is really a parasitic current drain.
-----Original Message----- From: Mercedes On Behalf Of Craig via Mercedes Sent: Saturday, March 28, 2020 4:24 PM To: Mercedes Discussion List <mercedes@okiebenz.com> Cc: Craig <diese...@pisquared.net> Subject: Re: [MBZ] Parasitic Draw On Sat, 28 Mar 2020 12:02:14 -0700 Jerry Herrman via Mercedes <mercedes@okiebenz.com> wrote: > Is a parasitic draw test a procedure that can be applied to any car? Yes. > The only "parasitic draw test" I know is disconnecting the negative > cable and then touching that negative cable to the battery post, > checking to see if there is a spark. There was a tiny spark, > indicating that electricity is being drawn from something. What should > I know about parasitic draw at this point in order to proceed? Put a test light in series with the ground lead of the battery as shown in the attached picture. Then start pulling fuses until the light goes out. You can see what connects to each fuse from the car's schematic and start eliminating each item which might cause the drain. Craig _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
