electrical fault - battery drain

[kingjami007]

Hi

i have a Renault megane 53 plate 2.0 salon/cabriolet (its the one with the card key and push start button). the other morning we had to call the aa with a flat battery and it turned out we have a 0.9amp battery drain which he couldnt find. we have located it to a certain loom, which is the one that goes to which i believe to be the maf sensor. its a round block that is attached to the engine block where the air intake come in. when we disconnect this and reconnect it to the battery the sensor makes a noise which sounds like a relay, could this be sticking maybe and causing the drain or could someone tell me if this goes off to other things e.g a fuse box and where can i locate the fuse box.

Untitled

• kingjami007
• 13 Aug 2014
• 1

the red circle is what i believe is the maf sensor making a noise. the arrow points to the cable...

any other info needed please let me know

 

[Belle427]

Looks like the motorised throttle actuator to me, it may benefit you to clean out the inside of this first (throttle body) you may need to reset it afterwards.
I cant quite remember the reset procedure but will try to find out.

 

[kingjami007]

thanks ch427. my partner took the car out to day and what ever she has done it has stopped the maf valve making a noise when i reattach the battery, gd news i hope, however the drain still exists, there for im guessing i need to find the fuse box to which it supplies, any ideas where this would be. if i where to remove the fuse and put my amp meter in series with it im hoping i can work through them one by one and find the drain. thanks again!!

 

[kingjami007]

i have also just tacken the fuse cover off and found that the drain goes to the fuse box but not sure which one how is the best way to find the drain. cheers

 

[freddiemercurystwin]

If you get no luck here you can try the forums on www.meganeownersclub.co.uk

 

[Belle427]

i have also just tacken the fuse cover off and found that the drain goes to the fuse box but not sure which one how is the best way to find the drain. cheers

Usually by disconnecting the battery positive terminal and connecting an ammeter in series with it. You need to be careful not to turn on any high demand items as the ammeter will only be rated at around 16 amps or less and could be destroyed.
You can then remove fuses one by one until the drain disappears.

 

[kingjami007]

Brilliant, will try that tonite once I have found the fuse how do I identify what it is doing.

 

[Belle427]

check what does not work or look at the fuse chart.

 

[KingboyD]

Most automotive MM which measure current in Series are rated for 10A, the unit will not be destroyed (unless it's really cheap & nasty) but the internal fuse will blow if you overload it, if you have a MM that will measure current in series then connect it between the battery V+ & the V+ terminal on the vehicle loom, once connected & the MM is reading current draw of say over 0.2A (200mA) then that is a drain & you can start pulling fuses 1 by 1 & see when the drain vanishes!

Can you get your hands on a clamp type meter? I have one for work & it makes checking for current draw easy! Also has a range of 0A - 1000A

 

[kingjami007]

Hi kingboy thank you for your help the mm I have is 10 amp unfused however is quite old and not really bothered if it blows. I am going to do the work this afternoon so will let you guys know how I get on.

 

[Spark123]

You will be bothered if you get it wrong and it blows up in your face or sets fire.