[morty]

Search provided nothing useful on this. This must have been covered before, but the answer is elusive.

I'm looking to add additional 12v lighting to the footwells/bottom side of the dash. I'd like this lighting to work like the cabin lights when set to door/open mode (middle selection on the 3 way rocker switch on the overhead light). When the door opens, give these new lights 12v and they should turn on.
My question is, is there a simple fuse to tap into that only gets power when the door opens? I tested the interior fuse panel and didn't see any behave this way. If there isnt a fuse that works like this, is the next simplest solution to just tap directly into the power going into the overhead light?

Thanks.

 

[keeponvaning]

No it’s controlled buy the computer. Your best bet is to splice into one of the existing lights for power but use all 3 wires.

 

[diytech]

I just got through doing this when adding the ambient ceiling light.

On the upfitter's accessory connector on the B pillar, there is a connection (pin 1 or 7) for a special 15 minute timed-out +12V for lighting. This will turn on a light when a door is opened, and shut it off after 15 minutes (no dimming).

There is a wire bundle running from the back of the van that picks up the little plastic cargo lamp above the back door. The wire bundle runs under the plastic cover in the passenger footwell. I tapped into the white wire for dimmed (PWM) courtesy light ground.

Anyone know of a more convenient place to grab these connections?

 

[morty]

Thanks Keep!
I assume the 3 wires are:

• constant 12v
• door open 12v
• negative

And all three are used by the factory on/off/on 3 way rocker switch.

 

[diytech]

Thanks Keep!
I assume the 3 wires are:

• constant 12v
• door open 12v
• negative

And all three are used by the factory on/off/on 3 way rocker switch.

The connections are:

• Timed 15 minute +12V power (red/white wire)
• Dimmed and timed ground connection for door open courtesy (white wire)
• Solid ground connection (black wire)

For your courtesy lights, you'd likely want the first and second connections.

 

[LarryK]

 

[morty]

View attachment 82041

Thanks! And interesting! I assumed that the 3 way switch was selecting 1 of 2 possible power sources (12v constant or 12v door). But it looks like its always connected to 12v and switching between which path to complete the circuit.

 

[diytech]

Thanks! And interesting! I assumed that the 3 way switch was selecting 1 of 2 possible power sources (12v constant or 12v door). But it looks like its always connected to 12v and switching between which path to complete the circuit.

Yeah, post OBD vehicles tend to avoid point of use chassis ground connections, and instead completes ground through the body computer module for fault detection, PWM dimming, etc.