Disco 1 D1 V8 - Parasitic Power Draw

Hi all,

Got myself a 94 Disco 1 V8 with a few issues, first of which is a parasitic power draw. It drains batteries flat in about 24 hours. Doing a power draw test and pulling fuses etc has determined it seems to be something related to the MFU - Multifunction unit.

This car has been semi-butchered in its life, and no longer has remote locking/central locking, and I don't believe it has an immobiliser either. (No key symbol on dash, keys are solid plastic moulded, no electronics etc), I also think the alarm is gone. It's a Japanese import, if that makes any difference.

Any ideas of where to start with this? I know that's a super vague question considering the above electrical bodgery that's went on over the years but would be interested to hear if anyone has had a similar experience.

As a jap import it does'nt have the alarm/immobiliser. The central locking was activated with 2 button fob. If it seems to be MFU check its not wet! a common fault is a leaky windscreen MFU gets wet and corrodes

The MFU has a diagnostic function, if you think theres an issue with it give it a try.
The procedure required is:
1. Close all doors and the tailgate.
NOTE: If the oil pressure switch goes open circuit (engine is started) during the following procedure, the MFU will exit the diagnostic mode immediately.
2. Press and hold the heated rear screen switch and switch on the ignition.
3. Release the heated rear screen switch within 2 seconds and the MFU will beep to indicate that it's in diagnostic mode 1.
4. Press the heated rear screen switch; the MFU will beep twice. In turn, operate each of the following switches, heated front screen, rear fog guard lamps, side lights, headlights, front wiper, and rear wiper. The MFU will beep twice each time a switch is operated.
5. Pressing the heated rear screen again will cause the MFU to enter diagnostic mode 2.
6. The MFU will provide outputs to the following in order given below: Heated rear screen relay energised for 2 seconds Heated front screen energised for 2 seconds Courtesy lights energised for 2 seconds Dim dip relay energised for 2 seconds Rear fog guard lamp energised for 2 seconds Headlamp power wash energised for half a second Front wiper energised for half a second Rear wipe/wash energised for half a second
7. The MFU will then exit the diagnostic mode.