Current drain or 'Dude Where's My Electricity'

[mjb59]

I knew this would happen- rejoin the forum and now presented with new challenges - thanks DJM 16!. As I said in an earlier post, I've been routinely unhooking the battery after every run as it was draining quickly. I gathered this was a leak or drain in the system and imagined 50yo wiring now cohabiting and surreptitiously mating in the middle of the night, leaving the battery spent and exhausted by morning. I presumed the answer was a new loom, which to me seemed like Everest from the North Face without oxygen.
DJM16 suggested removing fuses one at a time to localise. I found an old thread from 2009 discussing this. Can someone give me some more precise instructions. Do I have to buy a battery meter, check the charge, then remove a fuse, check the charge again after a day or 2, and therefore localise the circuit causing the drain? And then what do I do when I know which fuse is the problem? Do I have to check every wire on that circuit? It's good to be back - I think..

[Phil Nottingham]

The wiring may be suspect - dirty fuse box can cause this.  As said isolate each circuit first starting with the battery control fuse and then unplug the alternator relay plug. Do not start the engine with the plug removed

[enigmas]

If your looking for a parasitic drain on your car battery (and I gather you are) take a look at this vid from 'Eric the Car Guy' on Youtube. If you can use a multimeter it's a very straight forward process.

[mjb59]

Phil and Enigmas thank you very much for following up. I'll try out your advice and thanks for the link enigmas. I'll get back to you.

Not sure if it's relevant, but when I'm driving the car and the turn indicator is on, the speed/frequency of the indicator clicks/light will drop at idle and increase when the revs increase.

Does that imply that the battery is not properly charging when the car is running?

Michael.

[enigmas]

Hi Michael...if the indicators are flashing at different rates you either have bulbs of varying/mixed watts fitted or just as likely, bad ground/earth connections causing high/varying resistances. So check that all bulbs are of the same watts and clean all the earth connections to bright steel. Check each earth with a multimeter buzzer (ohms setting) if you have one.

[Warwick]

That video certainly highlights the electrical complexity and to some extent, absurdity, of modern cars. If you open the door on a P5 while you've got an ammeter measuring the current from the battery, you'd barely notice a change.
At least when you find the offending circuit, Michael, you won't have a hidden blood-sucking body computer attached to it somewhere.