I seem to have a drain on my battery.I tried some tests today.I took all the fuses out and connected my bulb tester between neg cable and battery negative. This showed quite a bright bulb even with all fuses out. Then i put my ammeter on it which went way past the 200 mamp range and so was unreadable.

I have traced the problem back to the thickest red cable which sits on top of the battery.I then follwed this to the relays under the dash and pulled each relay out ,the drain was still present.Other than this iam now stuck.

Any advice greatly appreciated.

i have a drain on my battery but i know what it is though

its the sub and amp ive got connected up to my new stereo, for some reason the sub and amp still have power running to them when the car is off i just have rewire them.

i take youve still got the original stereo in it as if its an upgrade that someone else has fitted it could be wired up wrong?

Thanks for reply yes still original stereo

Leave it a while (20 minutes?) before you test it after locking the car so that all the control units can power down.

Leave it a while (20 minutes?) before you test it after locking the car so that all the control units can power down.

Tried that but this is quite significant.

My battery measured 6 volts after 5 days before i recharged it.So i think it must be quite a drain.My local battery centre said battery was in good condition and held charge well.So am still puzzled.

I seem to have a drain on my battery.I tried some tests today.I took all the fuses out and connected my bulb tester between neg cable and battery negative. This showed quite a bright bulb even with all fuses out. Then i put my ammeter on it which went way past the 200 mamp range and so was unreadable.

I have traced the problem back to the thickest red cable which sits on top of the battery.I then follwed this to the relays under the dash and pulled each relay out ,the drain was still present.Other than this iam now stuck.

Any advice greatly appreciated.

Ok tried my new multimeter out today. My car drain gave a reading of 0.82amps. Does anybody have any idea what could be draining the battery of my pride and joy?

Cheers

See below.

A guess here, a faulty diode in the alternator? A diode allows electricity to move in only one direction, the alternator carries an arrangement of diodes (rectifier pack) which rectify the AC current produced by the alternator to the DC current that the car uses. If a diode fails it will let the electricity flow both ways draining it from the battery. You could test this by disconnecting the thick cable from the alternator (be very very careful not to let the free end touch anything , engine, bodywork radiator, anything metal or you will get sparks and possibly damage sensitive electronic units) and then measuring the current drain.

if you have a nice new multimeter, you can try taking each fuse out in turn and measure the current drawn through each fuseholder, that will give you a head start to identify at least which circuit is causing the drain.

As mentioned though, bear in mind some systems have a settling time before they turn off fully (imagine the interior light just as an obvious example)

totally thinking aloud here, but could possibly be a faulty switch in the tailgate for example, which leaves the courtesy light on in the boot, you'd never see it to know it was on..

Have already tried that With my bulb tester before it didnt seem to make a difference to bulb brightness. Not tried with multimeter but i carn't see it being much difference.when i connected the multimeter in series with battery it took about 10 seconds to die down to 082amps.Is this normal,i though it was maybe the ecu powering up and settling down?

Thanks for suggestion.

OK i may have found my problem.After connecting ammeter up and pulling fuses the problem seems to stem from the radio.When ammeter is in position safe mode comes on the screen. This seems to draw 0.50 amps its self if i switch off radio and lock doors reading is 0.03amps .Prob is i have to connect battery back up to make safe go out and radio return to normal but then i carn't read the multimeter with it all connected up.

Can a radio in safe mode really draw half an amp and would this go when in the normal working off mode?

Hope you can undersatand this.

Hi

After ten days the standard radio/CD on my Octavia 11 had drained the battery to the point where the car would not start !!!!

Appears to be a known fault to the local dealer who did some electronic wizardry to prevent repetition. Sorted under warranty.

Hi

After ten days the standard radio/CD on my Octavia 11 had drained the battery to the point where the car would not start !!!!

Appears to be a known fault to the local dealer who did some electronic wizardry to prevent repetition. Sorted under warranty.

Yeah octy 2s have stream radios i think but mines a mk1.Gonna try a new battery tomorrow and see if it starts to drain that

How are you connecting the ammeter to check the drain?

How are you connecting the ammeter to check the drain?

Have used ammeter, with radio button turned off i get 0.01-0.02amps which is nothing.But with radio on and ignition off and all locked up safe comes on even when locked and gives 0.5amp drain.

Once managed to get all locked up and safe off with radio button out.It gave 0.05 which again is nothing.I think its a bad battery discharging over a few days?