Johnny 216GSi wrote: ↑Mon Jan 01, 2024 2:39 am I'm taking credit for "the green and black wires" comment I made well before you found the problem.
Spot on but you weren't the first to have this problem...
Johnny 216GSi wrote: ↑Mon Jan 01, 2024 2:39 am I'm taking credit for "the green and black wires" comment I made well before you found the problem.
Thank you so much for your help! I'll give that a go.itcaptainslow wrote: ↑Mon Jan 29, 2024 2:33 pm A rough & ready, but effective, way of narrowing down what is causing the drain is to work methodically through the fuse box, pulling fuses individually to isolate various circuits (making a note of which circuit) and seeing if the battery still drains. Obviously when it doesn’t, you have found the affected circuit.
The process can be sped up significantly by purchasing and using a multimeter to measure battery drain whilst pulling the fuses. It’s worth waiting a few minutes before starting/between each fuse to allow the circuits to power down and residual current to dissipate.
I don’t have exact figures for the 25 to hand, but “normal” current draw with the ignition switched off and powered down shouldn’t exceed around 0.03-0.04 amps as a reasonable rule. You’ll be seeing way more than this with a flat battery in a couple of hours (that’s a huge draw!) - a healthy 52ah battery would last just over 20 hours with a 2.5 amp drain.
If you’ve an aftermarket stereo, I’d start there by disconnecting that…
On a side note, I would also take the battery to be tested at a motor factor/garage/even Halfords. You may find it has a knackered cell or two (especially if it’s been repeatedly flattened) and isn’t holding a charge correctly.
That is a very good “straight to the fault” shout - I had to replace my alternator regulator on my R8 a couple of years ago, as it turned into a power hoover from the battery!SteveB wrote: ↑Mon Jan 29, 2024 10:59 pm I had quite a significant battery drain on my 214 a while ago - turned out to be the alternator.
If you don't have a meter handy, an easy way to check is to unplug the alternator, wait a few hours (overnight perhaps - should be long enough if it's draining within a couple of hours), plug it back in and see what the battery's like. If it hasn't drained at all then you've found the problem. But don't run the engine with the alternator unplugged.
Thank you for the advice, I changed the alternator about two years ago but I didn't buy a great brand (broke uni student haha) so it might be that. I'll be sure to check itSteveB wrote: ↑Mon Jan 29, 2024 10:59 pm I had quite a significant battery drain on my 214 a while ago - turned out to be the alternator.
If you don't have a meter handy, an easy way to check is to unplug the alternator, wait a few hours (overnight perhaps - should be long enough if it's draining within a couple of hours), plug it back in and see what the battery's like. If it hasn't drained at all then you've found the problem. But don't run the engine with the alternator unplugged.
Thanks for even more advice!itcaptainslow wrote: ↑Mon Jan 29, 2024 11:22 pmThat is a very good “straight to the fault” shout - I had to replace my alternator regulator on my R8 a couple of years ago, as it turned into a power hoover from the battery!SteveB wrote: ↑Mon Jan 29, 2024 10:59 pm I had quite a significant battery drain on my 214 a while ago - turned out to be the alternator.
If you don't have a meter handy, an easy way to check is to unplug the alternator, wait a few hours (overnight perhaps - should be long enough if it's draining within a couple of hours), plug it back in and see what the battery's like. If it hasn't drained at all then you've found the problem. But don't run the engine with the alternator unplugged.
Unfortunately, the location of the alternator right next to the exhaust manifold means it gets a bit hot…
You can also check this by checking the charge rate of the alternator with the engine running using the multimeter across the battery terminals - it should be a steady 14v. Mine was fluctuating all over the place, from 0v to 15v! Another symptom of a knackered regulator.
You can replace just the regulator rather than the whole alternator - it’s a fair chunk cheaper.Scarlett Orr wrote: ↑Tue Jan 30, 2024 8:52 amThank you for the advice, I changed the alternator about two years ago but I didn't buy a great brand (broke uni student haha) so it might be that. I'll be sure to check itSteveB wrote: ↑Mon Jan 29, 2024 10:59 pm I had quite a significant battery drain on my 214 a while ago - turned out to be the alternator.
If you don't have a meter handy, an easy way to check is to unplug the alternator, wait a few hours (overnight perhaps - should be long enough if it's draining within a couple of hours), plug it back in and see what the battery's like. If it hasn't drained at all then you've found the problem. But don't run the engine with the alternator unplugged.