Battery Drain - how to meter the circuit

[Sharknose3]

I've traced a battery drain on my 320 Touring to Fuse 20 (Heater blower, air conditioning (relay K7)).
I've replaced the relay and the drain is still there so for the moment I've removed the fuse.
The car has no aircon.

Can anybody give me some hints as to how I should meter through that particular circuit with a multimeter to find whether I have a short to ground, some botched wiring or a dodgy heater draining my battery?

The winter is coming and it might be better to have a heater

Thanks in advance,
Sharknose

[Brianmoooore]

Fuse 20 should have no power on it when the car is parked up with the key out. Something odd here.
Only fuses 21 to 28 should be posible candidates for battery flattenung leakage currents (+ altenator regulator pack).

[Sharknose3]

As this is definately the fuse that drains the battery, it sounds to me like I need to look for dodgy wiring and what else might have been added to the circuit. I'll put back in that fuse and see what I can find out. The car has "after market" electric windows that might be suspect.

Thanks for your help Brian.

[Brianmoooore]

Fuse 20 is dissconnected from power by relay K7, so if there is power at 20 with the ignition off either the relay is on permanently (does it click when you plug it in?) or the relay is jammed on (faulty relay or wrong relay? 30 and 87 should be open circuit with relay out of car ).
If the relay is being powered on,then there is a problem with the green/white ignition supply which comes straight from the ignition switch green supply via fuse 10.
Another possibility, if the relay is powered on, is inncorrect wiring on the starter motor, somehow feeding power back to pin 85 of the relay coil.

[Sharknose3]

Turns out that a sticking K7 relay was the problem, I replaced it and all appears to be ok now,

Thanks a lot Brian

Sharknose