71 Firenza phantom drain

[CanadianFirenza]

Hey Folks!

I have a 1971 Vauxhall Firenza SL 2000 4Speed manual Canadian Market car that I regularly drive.

I have batteries drain somewhat regularly and have failed to find the source, I am curious if there is any advice on how to find my issue. The only thing not working currently on the car is the windshield washer fluid pump which is getting power but not firing and planned to be replaced/changed in the future. The volt meter jumps all over when connected while running usually. Everything else seems to be reading correct volts and amps throughout the car and have yet to find a bad ground BUT it may exist.

I keep a volt meter in the car just in case and have seen batteries dip to <10v regularly. I just installed a new battery again when the previous died and want to try to solve this ASAP as to not kill another battery or end up stranded.

I could not find a thread on this specific issue for my model so figured I would try a new one!

[droopsnoot]

I believe a good way to find battery drain is to connect an ammeter in series with each circuit in turn, and see what's still drawing current while it should not be. Is this happening while the car is running, or while it's left?

[jpsmit]

I believe a good way to find battery drain is to connect an ammeter in series with each circuit in turn, and see what's still drawing current while it should not be. Is this happening while the car is running, or while it's left?

there is a number of good videos on parasitic drain.



On my MG I had the same issue with the battery draining after a few days. I got very lucky - and there are only 4 fuses - but, it was a dirty connection in the fuse itself which was providing resistance and therefore current draw.

If however it is draining when it is running, it is the alternator.

when you get the car running properly (other post) put your volt meter on the battery with the engine running - it should show about 14.4 volts - any less and it is likely the alternator or a bad battery.

There is a guy north of Toronto who rebuilds classic alternators.

[CanadianFirenza]

Thank you for the responses!

@droopsnoot:
Mainly happens when the car is sitting not running, I started going down this path but found nothing drawing when it was off yet... I will redo my work and ensure I am not missing something thank you!


@jpsmit:
Fine when running alternator seems to be in good shape, but drains sporadically when sitting which keeps pointing me back to a bad ground connection or some other dirt but have not found it yet, video seems to be what I have been trying; but as per above; I will redo my work when I get another time block to get into this car. Past battery was hitting below 10v often, new battery is fine, may just leave it disconnected until I diagnose as to not wreck another pricey battery!

I will post back when I know more and I greatly appreciate the responses from you both, lots to recheck!