Postive plugged into ignition.

Negative on hood latch.
Hi all,

I'm looking to power a magsafe charger from the 12V IGN source under the dash with a DROK Stepdown converter.
Currently have a (+)16ga from the 12V IGN to my Converter and the (-)16Ga ground on my hood latch bolt.
Problem is, it seems to be draining the battery even when not in ignition. I've checked the wires and there doesn't seem to be any contact to be shorting the battery.
Would the ground location cause a parasitic drain?
Any advice would be greatly appreciated.

Thanks!

 

Are you still getting voltage from that location even when the key isn't in the ignition? Bust out the trust multimeter to confirm

 

Hi,

Checked with the multimeter, only the port in the middle(Batt) had voltage with car off, the top(Light) and bottom(IGN) had no voltage in off position but had voltage with car on.

 

And you're sure that the parasitic draw is coming from the other terminal? When you remove the spade plug you just installed, no parasitic draw issues?

 

Yeah, never had a problem till I added the spade last night, woke up this morning and the dash was flickering as I tried to turn it on.
Didn’t have enough power to turn it on so had to get it charged at autozone.

 

any chance you left a dome light on or anything after you were done working on it?

Unrelated to a parasitic draw, but you should consider adding an inline fuse to your (+) wire near the fusebox - IIRC that terminal has a 40-amp fuse and in the event of a short that wire can't handle that much current.

 

oooph, I don’t think I had the dome on, but now I’m having second thoughts. Will check that out.

Will add an inline fuse to the (+) wire, thanks for the input.

Do you think the ground location or the step down converter might be the issue? Or should it not matter since it was plugged into the port that should have no voltage coming through while the car is off?


thank you!

 

If there's no power at that accessory terminal with the engine off, there can be no parasitic loss from your circuit.
That terminal is switched by a relay, which if it got stuck in the on position would keep that circuit energized, but other circuits would also be energized so you'd have had the problem anyway.
You can measure the current draw with your multimeter -

• remove the key so you know everything is off
• disconnect the (-) terminal at the battery
• set your multimeter to amps - even though the draw with everything off should be in the milliamps range, use a setting and probe connection for say 10 amps because you don't want to blow the fuse in multimeter if you really do have a big parasitic draw
• put the meter between the battery (-) terminal and the now disconnected ground cable, and measure the draw. It will be non-zero because some circuits remain energized like the keyless entry but should be below 50 mA. If your battery drained overnight it would be way way higher though