S3 - Electrics completely die! then come back on - Earth on battery?

[Schlaag]

Hi guys, recently the car has been completely electrically dying when i put the key in the ignition. Total power loss as if someone has disconnected the battery.

Then sometimes it comes back to life.

Never dies on driving the car.

Last night it did the same so I popped the bonnet, and slightly touched the earth cable leaving the left side of the battery and the car sprung back to life

Do these cables corrode?

It is securely clamped to the battery terminal, I cannot yet get to the cable as it goes from the battery to wherever....

Would one earth cable cause the electrics to fail so prominently?

Thanks
Dave

 

[<tuffty/>]

They corrode under the battery tray... there are a couple of earthing posts there

<tuffty/>

 

[Schlaag]

update it's not the earth cable, its the thick black positive cable coming off the left side of the battery and down under the battery tray.

any idea where this goes?

 

[<tuffty/>]

Starter motor...

<tuffty/>

 

[Schlaag]

Morning mate, that makes sense. But would a bad connection to this cause the whole cars electrics to go??

Exact scenario is this:

Walk to car, unlock remotely, keys in ignition, dash lights up, go to crank... CLICK all power goes. Lights, dash, stereo, alarm... everything.

Only resolution is to wiggle that cable to the starter then power is resumed.

 

[s3dave]

Yes because that is the main earth source..

 

[<tuffty/>]

Main positive electrics feed is from the fuse box on top of the battery... there is a thick feed wire coming off the positive clamp that goes to this... check this fuse box...

<tuffty/>

 

[Schlaag]

will do, thanks guys