Draining Battery

[snoopdutt1985]

Hi all,

I am having a continuos problem with my 1.6 vvt 52 megane.

I have had numerous auto elecs out to it and had it in a garage also with no luck so far, we did find a strange wire going to the earth of the battery and removed it we thoguht we had solved it 6 weeks later its dead again.

The alternator has checked out fine, as has all diagnostic fault codes, just a slight problem with the 02 sensor but this is not related.

The battery is draining itself over and over again sometimes lasting as little as 3 days other times 6 weeks.

I have a sensor missing for the alarm in near the boot lid, could this be causing an electrical problem?

Could constant re chariging of the battery means its the battery that is knackered?

Sometimes in the process of dying the alarm starts to sound very quietly? related???

Apart from that the car is fine, starts first time, pulls nicely, the lot. just wont start!!!!

Any one else experiencing anything similar.

Cheers,

Andy

[AlexB]

The standard procedure in case of any trouble with the battery older that 4 years is to replace it with the best you can find. This is what the dealer would do.

You may also check the battery and the alternator by using the procedures described in the manual, see my message in Links (download the PDF files).

Then one can measure the current used by the deadlocked car. If it is excessive, then check the currents across each fuse. One of multiple controllers in the car may stay active due to a fault in the on-board network...

[snoopdutt1985]

thanks for the reply alex, i have replaced 2 batteries within 8 months.

The current has been checked on the deadlocked car by multiple auto elecs and all appears to be normal and stable. As for indiviudal fuses have not been checked, there is just so much to get through with so much electrics on the megane.

Keep the help coming, much appreciated. the best part about owning a megane is this helpful forum!

[AlexB]

Presumably the alternator was also checked... Then it is some sort of an intermittent electrical fault -- these can be very hard to locate.

[snoopdutt1985]

Yea alternartor is also fine, Intermittent fault it is then...running out of patience with it now and thinkin of gettin shut just not willing to except bottom doller for the french piece of sh1t!

[nagogg]

Not sure what manufacture year your car is,but reading throught your history there comes 2 issue in my mind,which are rather common.
Go to a dealer and check if theres fault on the Camshaft sensor,and also check the software vers of the Inject Comp.Software under Vers 74 has been making issue as you decripe,and the proplem lies in the Camshaft sensor and the inject software,it causes irregula current draw.
If faults is present replace the sensor and reprog the Comp.
The second one is water entering the UPC in the engine Comp.It also can cause irregular current draw.
Remove the UPC unit,open it and check for oxydation.
Good luck

[snoopdutt1985]

i have had all sensors checked through ECU, the only one that came back a bit ropey was the O2 sensor.

I have just had a new battery fitted and put some good motorway miles on the clock and all appears to be ok for this week at least.

Next step is defo to renault , but i have heard nothing good about renault garages, especially in my local area, greater manchester,

for the record my megane is one of the first mk2, 52 reg, 03 regsitered. will this make the software out of date?

Thanks for the help

[AndyS]

Apologies in advance for what is probably a very stupid suggestion, but have you checked the footwell lights? Some models have switches in the underfloor "secret" compartments (beneath driver's and front passenger's feet) which switch on the footwell lights when these compartments are opened. If not properly closed, they may bounce open/closed while you're driving, sometimes leaving the lights on, sometimes not.