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Door Contact Voltage

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Old Sep 16, 2019 | 05:17 PM
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Default Door Contact Voltage

I'm looking for some electrical help. What should the voltage be at the door contacts that turn on the dome lighting (i.e. at the brown/white wire connected to the door switch)?

I am getting 7.6V at both door contact brown/white wires. The switches have been cleaned and work as intended, keeping the interior dome lights on for ~20 seconds. The alarm module internal relay clicks as it should.

I've followed the wires from the doors, through the A-pillars, and under the dash and the plastic sheathing around the wire is intact.

I would've thought that the voltage should be 12V, similar to the frunk and engine bay lighting brown/white wires.

Thoughts? Could someone check this on their car?

Thanks.


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Old Sep 16, 2019 | 06:19 PM
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JohnK964
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I thought those wires were grounds as in with doors and such closed no contact open they goto ground
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Old Sep 16, 2019 | 08:53 PM
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I thought so too. The electrical diagram isn't that helpful.

The door switches work as intended so it's weird.

Don't know if someone wouldn't mind using a volt meter and putting one lead on their switches and the other to ground to see what they get. Maybe my alarm system is wonky.
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Old Sep 17, 2019 | 02:19 AM
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Measuring voltage on the door switch is not very relevant. There is a weak pull-up resistor in the door lock control unit, and the switch grounds this when the door opens. The GND signal is the one that triggers things, not the pull-up voltage.

Cheers,
Tore
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Old Sep 17, 2019 | 07:23 AM
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Thanks Tore!
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