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Renault Master Battery drain

33K views 11 replies 3 participants last post by  davelee002  
#1 · (Edited)
Renault Master 2011
Ever since I bought my van the battery has drained to a point where it won't start the engine after a short time. Originally that was around a week, now it is a couple of days being left. I did a drain test by removing fuses with an ammeter connected and found a fuse in the engine bay that made a dramatic difference to the amps reading. (From 0.8amps to 0.07amps) Trouble is there is nowhere that shows what particular circuit that fuse is for. In the image it's the one marked with a piece of tape. Anyone know? TIA
Image

My feeling is the problem is the rectifier in the alternator but access is awkward and I just wondered what the fuse feeds before I start dismantling to get to the alternator.
 
Discussion starter · #4 ·
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.
 
Discussion starter · #6 ·
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.
 
Discussion starter · #9 ·
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.
 
Discussion starter · #10 ·
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?
 
Discussion starter · #12 ·
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.