Battery Drain Mitsubishi Magna - Door Jamb Light Switch - 2002 TJ - Flood Water

Update: I replaced the switch and still registered 13 Ohm! No idea why the passenger door does not do the same thing. Possibly an issue further down the circuit, but since its all hidden there isn't much I can do.

I used a multimeter across the battery terminals to identify a low resistance when the driver's side door jamb light switch was 'on' [when door is open] of 12.8 Ohm. This would lead to about 1 A of current or 13 W of power draw (for a ~13V battery) when the battery is installed. I will replace the switch. It's also possible my 8 year old battery does not have a lot of capacity, and goes 'flat' too quickly. Another way of checking would be to install the battery and measure the current flow through the lead when opening the door.

The switch is very low and may become faulty from driving through water. I didn't show it in the video, but the low resistance of 12 Ohm can't be reproduced if the driver's door is closed and the front passenger's door is opened instead. When the switch is 'off' there is over 1000 Ohm of resistance, which isn't low enough to draw down the battery at a problematic rate.

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