Our wrenching buddy JB1 had the battery completely drained after parking the car for some days.

He jump started the car and heard relays chattering(clattering?) under rear seat because of the low battery voltage. So he suspected the GM, RM or the ADM .
Usually the ADM (Anpress Druck Modul German for wiper pressure module) increases the wiper pressure at the following speeds: >5, 100, 140 und 180 kmh.
Many people have found that a faulty ADM is the cause of their flat battery. The easiest way to test is to look under the rear seat driver side LHD and pull the black relay marked ADM.

When the battery voltage is OK but the relay is broken, the motor never switches off.
After recharging the battery the relay stopped chattering but the pressure motor could be heard clearly running. Other possibilities: limit switch broken at the wiper pressure motor, or the GM, but mostly the relay.
He checked the online ETM, but the wiper pressure system is not included in the US version. Then he checked the Japanese ETM, it showed the wrong position for the ADM relay.

We have the correct document here

the ADM fuse is here


ADM serial number is here
Specification of ADM
BMW HELLA
ADM 12V
61.35 1 378 371
4 RD 005 173-00

ADM pin outs
7 Pins:
AR+, AM+, 30
AM-
AR-, 31, DA

this is inside the ADM - these are the 2 transistors that often break.


From the expert: Fuse No.22 is power supply to wiper pressure motor so if you take this fuse out, the motor should stop making noise.
After relay was exchanged, I opened faulty one and measured transistor resistance.
If I compare with good unit, it shows leak between base-collector, (good test )


normally base-collector shows infinite. (bad test)


Transistor used was TO-92 BC337 from Fairchild, Vceo 50V Ic 800mA Pc 625mW.
I did not have one so I ordered similar spec transistor 2SC2120 35V 800mA.
Will see if changing TR's will fixes problem or not.
You can take out ADM unit, without removing cover of GM or Relay Module.

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Tools:
Digital or Analog Multimeter with DC Amp scale of about 100 milliamps (mA)

Background:
When the car is fine and healthy there is only a sleeping drain of 30 mA, higher than this will drain the battery quickly depending on battery condition etc.
Evil drains can be either failed devices or failed wiring. Good drains include the radio, EML and DME.
All power supply wiring should be fused, some also have a relay, most have a switch --
so the typical circuit is battery -> wiring -> switch -> relay -> fuse -> device -> earth -> battery

Point 1: download and study the circuit diagram for your model from here
Point 2: The E32 enters sleep mode 16 minutes after the last activity -- usually closing the door.
Test:
- remove the rear seat, wind down the rear windows
- prepare two good gauge wires long enough to reach the engine compartment if you are working alone -- the wires should have crocodile clips at both ends.
- set the multimeter at about 5 A DC to begin with
- connect the wires to the leads of the multimeter (be careful not to short them out), and plug the leads into the multimeter
- connect the free end of the positive multimeter wire to the clamp on the battery's negative terminal
- loosen the clamp and, while still keeping contact with the terminal, raise the clamp until you can connect the negative multimeter wire to the terminal, lift the clamp up and isolate it. This ensures that the radio does not loose its security code! But you have recorded the radio code just in case, right?
- close the door and wait the 16 mins, the multimeter should show a drop in current.
- change the multimeter scale to read about 100 mA
- now remove the fuses one at time and check for any sudden drop in current -- the fuse yielding the drop is on the circuit holding the evil drain.
Point 3: leave the fuses for the radio DME and EML to last -- hopefully the bad circuit is not one of these!
Point 4:If you have removed all fuses and the current flow is still present, then the wiring/connections between the battery and the fuses is at fault OR
Point 5: It might be possible that the insulation on the cable from the alternator to the + post in the engine room is damaged, so disconnect the cable at the post and check
- if you find a bad circuit, reinstall the fuse and then remove the device; check if the current falls again.

If it does not, move back up the circuit device -> fuse -> relay -> switch and check each part.
You will nail it with enough persistence!

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