I recently bought an Octavia VRS estate (56 plate). 2.0l diesel.

 

I think its has a parasitic drain on the battery...

 

On cold mornings it struggles to start and you're turning the engine over for longer to get it going. 

 

I bought a new battery for it when I got it as the one in the car didnt look big enough or match the spec of those recommended for it. 

 

When the car is running the voltage across the battery is 14V. 

 

I tried a parasitic test by disconnecting the negative terminal and connecting a multimeter between the negative post and ground and then pulled out each fuse in turn to locate the current draw. I didn't find any of the fuse made the current drop. It was showing around 1amp of drain but im sure that's wrong. 

 

Do I need to allow all the systems to power down for a certain amount of time before I conduct the test?

 

Are there any common area's I can look for, for this type of fault?

 

Do I need to lock the doors?

 

Could the diodes have gone in the alternator? 

 

Any help would be great.

 

Thanks

 

from memory,  the body? unit takes approx 40 minutes to close down

Pulling fuses out is likely to cause modules on the CAN-bus to wake up and confuse your results.

 

Instead, you need to override the boot and door switches so that you can access both fuse panels while the car is 'locked' and asleep. By measuring the mV and using a chart you can calculate the current.

 

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