Mk7 heated screen!

[VanManMax]

Hey guys- I apologise if this has been covered before and if it’s in the wrong section. But I’m after some advice on my 2009 T280, it’s got all the wiring needed for a heated screen- it even has the heated screen fitted! Both relays are there and when removed I can see all the terminals beneath, it’s got both 40A fuses and cables from the fuse box behind the drivers seat etc, etc. But for the life of me I can’t get it to work, everything is connected, the switch just won’t do anything! I’ve tried another switch out of a friends van- still the same. The switch doesn’t light up, only illuminates with sidelights turned on. I’m so confused as everything is there!

Any help would be greatly appreciated.

[Mad Husky]

Duff relay ?

[VanManMax]

Duff relay ?

Would the switch not light up with a dead relay?


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[Altransit]

Engine running?


Have you tested for power at the screen terminals, and at the relay terminals? Checked the earths?

[VanManMax]

Engine running?


Have you tested for power at the screen terminals, and at the relay terminals? Checked the earths?

Yep engine running, got power at relays but nothing to screen ribbons.

Earths appear to be connected below the dash, black wires on posts with 10mm nuts.


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[Altransit]

Was the screen an original fitment, or put in later

If the latter, you need to "tell" the BCM that the van has a heated screen

[VanManMax]

Was the screen an original fitment, or put in later

If the latter, you need to "tell" the BCM that the van has a heated screen

That’s my next thought, van had a non- heated screen fitted when I bought it. But the bloke I bought it off said it was heated, but he had a non- heated fitted as he didn’t go through insurance. So that’s why I had a heated screen fitted, so I could utilise the wiring/ relays.

Sorry, I know that’s hard work to read.

But would you say I’m missing anything obvious? There’s no other fuse for anything related to the screen somewhere I haven’t seen?


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[Altransit]

I believe that there are fuse for the HFS under the drivers seat, but I'm not 100% sure

[Punto443]

Those feeds under the seat are the high current ones to the relays, sounds like the prob is just on the low current switch side.

[VanManMax]

I believe that there are fuse for the HFS under the drivers seat, but I'm not 100% sure

Yeah I tested both sides of both 40A fuses, 12volt present. I’m pretty adamant it’s been ‘turned off’ via IDS.


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[VanManMax]

Those feeds under the seat are the high current ones to the relays, sounds like the prob is just on the low current switch side.

I have power to the dash switch if that’s any use?


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[Punto443]

From memory the screen controlled by the bcm and it’s negative switched through it.
This may be a configuration issue instead of a wiring one?

[VanManMax]

From memory the screen controlled by the bcm and it’s negative switched through it.
This may be a configuration issue instead of a wiring one?

Does this mean I need someone with IDS either way?


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[Altransit]

Either that, or you need to run a separate feed to the relays, via a different switch not controlled by the BCM

[Punto443]

Nip up to my house and I’ll check it for you