VT Interior Light Switch Not Working

[greekplaya]

Hey Guys,

I recently added the rear courtesy lights to my VT. I already had a Calais spec centre light installed with LEDs for the main and map lights. The rear courtesy are LEDs as well and I used the harness from a Calais to wire in the courtesy lights. When I unlock the car all the lights come on and once the doors are closed all the lights switch off. However, it doesn't matter where I have the switch on the main light it will always come on when the doors are opened and off when they're closed. The map lights will work off their switches but I am unable to turn on the main light via the switch. Has anyone else had this issue?

I read something about needing a Police spec light for it to function correctly as it has something to do with the BCM or having to desolder a connection but I couldn't really understand what they were explaining.

 

[greekplaya]

I had another quick look at it last night as I thought it might not be grounding properly and could see the grounding plate for the map lights, but the main dome light LED was still on even when unscrewed from the roof.

Does anyone have any idea what might have caused the switch to stop working as it previously did?

 

[colourmesilver]

the contacts are dirty? reversed wiring? use a torch man, interior lights lets every see what ya doing inside ya car

 

[kyled2012]

VT Exec dome lights had the switch on the ground wire, meaning the dome light bulb always had +12v connected. The BCM controlled the 'doors' wire.

VT Calais was the opposite, the bulb always had Ground, and the BCM switched a positive (+12v) wire.

To fit the Calais light, it isn't plug and play, and you would have to alter the loom or the switch itself.

If you wanted it to be plug and play, the Police spec light uses the same wiring as the Exec (switching ground)

Altering the wiring won't be hard mate, you just need to put the negative wires into the switch, and the positive wire to the opposite side. I'll post up a labeled pic of the Exec Wiring later if you need.

 

[greekplaya]

VT Exec dome lights had the switch on the ground wire, meaning the dome light bulb always had +12v connected. The BCM controlled the 'doors' wire.

VT Calais was the opposite, the bulb always had Ground, and the BCM switched a positive (+12v) wire.

To fit the Calais light, it isn't plug and play, and you would have to alter the loom or the switch itself.

If you wanted it to be plug and play, the Police spec light uses the same wiring as the Exec (switching ground)

Altering the wiring won't be hard mate, you just need to put the negative wires into the switch, and the positive wire to the opposite side. I'll post up a labeled pic of the Exec Wiring later if you need.

If you could post up the labelled picture that you mentioned I'll give it a go.

I had a feeling it wouldn't have anything to do with the harness itself from all the wiring diagrams I've looked at the wiring into the lights is the same regardless of spec.

 

[kyled2012]

Yeah the wires coming into the lights should be the same regardless, so I'd say you'll just need to change the wiring on the light itself. I'll throw up the picture when I get home from work mate.

 

[Nut Kracker]

Interior and Instrument Lighting VT and VX Executive and Berlina models.



Interior and Instrument Lighting VT and VX Calais models

 

[greekplaya]

Thanks for the wiring diagrams they're a lot clearer than the one's I've looked at

 

[kyled2012]

The wiring diagrams from Nut Kracker will be the best references.

All I had was these basic pics I took of my exec when I hooked up the Sunnies holder.

 

[Nut Kracker]

Wiring diagrams are all well and good if you understand them, but there's nothing like an illustration ^ to go with it.