Update: Having taken the wire off the alternator, I still get the same drain reading as when it's connected so maybe not the alternator.

 

What size engine,,, is it a mark 2, or mark 3

 

MASTER III 2.3 DCI FWD DIESEL

I've taken all fuses and relays out one by one and this is the only fuse that makes any difference.
I tried taking it out to see what didn't work and there was very little working, no dash display or starter so it is clearly feeding a fair few circuits.

 

It covers, fuse 27 engine bay fusebox
1, 4, 10, 11, 22, 27, Passenger fusebox
No 27, engine bay = horn
1 = radio
4 = accessory socket
10 = control unit, abs/esp control unit, esp sensor
11 = heating controls, door lights, mirrors, light sensor, brake lights switch, interior lights.
22 = alarm, audio.
27 = blower control unit...
Might be time for auto electrician :frown2:

 

Update: The battery was worse than I thought and after being disconnected for 2 days it wouldn't start the van so a new battery was fitted and although that put me back to where I started 2 years ago at least I can leave it for a few days and still start it.
It was booked into an auto electrician and after two days of searching they came to the conclusion that the reversing camera in standby mode, connected to the radio circuit, was the likely cause. I was told the 70amp fuse I pointed out powered too many things to be a useful indicator.
Admittedly when the camera is disconnected the drain drops from 0.8 amps to around 0.4 amps but surely that is still more of a drain than it should have.
I'll put a switch on the camera to isolate it to help matters but I'm now at a dead end.
Auto electrics is an area I've avoided but if it has baffled an auto electrician it looks like I will have to live with it as it is.
I'm going to remove the tachograph at the weekend and see what difference that makes.

 

Were you brave enough to remove all the fuses listed.
Take them all out, measure the amp draw, then replace one at a time...
This will then point to the circuit..
Then come back on, see if someone can then help you

 

Assuming you have a 100Ah Battery & you drive for long enough to recharge fully, 0.8 Amps will kill enough of the capacity for it not to start in 100 Hours or less. Which is 4 Days Max. Even 0.4 Amps, IMHO is too much.
Typical residual drain is more like 0.05 - 0.1 Amps to run clock, radio memory & Alarm / Immo.
Tacho seems like a good idea.
I have also known Alternators to go leaky & one can't turn them off. :frown2:

 

Nottnoc - If I could get close to 0.1 amps I would be more than happy. I disconnected the large wire from the alternator and it made no difference so I think that means the rectifier is ok. There is a smaller wire that is difficult to get to that I believe energises the alternator coils which I wonder about.

ours2012 - I haven't removed all of the fuses totally. Even with a photo I would worry about getting them back in the right place. That 70 amp fuse seems to be the key to me even though the auto electrician dismissed it as unhelpful. The fuses you listed all seem to check out ok.

I read that if the alternator was at fault it would feel warm after standing overnight. That got me thinking that whatever is drawing half an amp is likely to be warm - I have even considered trying to get hold of a thermal imaging camera to see if it shows anything warm !! That's how much it's annoying me.

 

Disconnecting the rear view camera reduces the drain to around 0.4amps.
Disconnecting the tacho reduces the drain to around 0.2amps.
That is almost acceptable. The only problem now is that the odometer mileage doesn't show on the dash display, only on the tacho.
I had hoped the mileage would miraculously appear on the dash when the tacho was disconnected - no such luck so I assume it needs reprogramming with the Renault software?

 

Can you now re-route those feeds to be switched via the ignition? So that current is only taken whilst vehicle is charging.
The tacho of course, is designed for vehicles driven daily, so drain of that order was never an issue.

 

I may well rewire it to an ignition fed +ve.
The slight downside to that is when power is applied to the camera system, by default the monitor display comes on so it's probably less trouble to fit a switch to use the camera when needed rather than have to turn it to standby every time the ignition is turned on.
But I appreciate the suggestion.
I agree that a vehicle with a tacho is probably not left standing for long like mine is.