Switching Relay With Open Signal

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=143433
Printed Date: May 12, 2025 at 1:50 PM

Topic: Switching Relay With Open Signal

Posted By: topic 844
Subject: Switching Relay With Open Signal
Date Posted: August 04, 2017 at 3:25 PM

Hi,

I'm trying to install a courtesy LED light above the driver and passenger door on a Ford Transit 2016
found the signal for open/closed door, however it is the opposite of what I need.
Door open: N/C (open signal)
Door closed: Ground signal
If it would be the opposite would be so easy, power to LED one side, the Transit Door open signal
to the other side and done.
But now I'm stuck I can use Relays, resistors and diodes, but not much else to keep it simple
Does any one have a suggestion how to connect it?

Replies:

Posted By: wirewise
Date Posted: August 04, 2017 at 6:58 PM

There should be a Gray/Yellow (-) output trigger wire at the BCM, Brown 46 pin plug (B), Pin 2. The BCM is located at the dash fuse box.

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~wirewise~ Verify all wiring with your meter before making any connections!

Posted By: topic 844
Date Posted: August 08, 2017 at 11:32 AM

Thanks Wirewise!

Is this a negative signal when door open?

I will definitely check it out.

Posted By: topic 844
Date Posted: August 15, 2017 at 12:30 PM

Wirewise,

I found that wire and yes it works, but it acts same as the dome light,
and for my application the light should be on only when door open and stay off
when door closed.
There is an output from Transit for the cab doors at the "High Specification Vehicle Interface Connector"
behind the glove box. pin

posted_image

on pin 17 for Passenger door ajar (door closed=ground)
on pin 18 for driver door ajar (door closed=ground)

I need a ground when door open not when closed any ideas?