mk2 wiring diagram

petet16 · 13-03-13, 02:18 PM

As the title really, I need a wiring diagram for the mk2 heated rear window switch.

I've got a switch to use for my heated windscreen when it turns up, and just need to know which terminals on the switch do what.

Thanks

stamford · 13-03-13, 03:21 PM

My god, one to put in the calendar people, Pete needs our help!

I take it the mk1 is too dissimilar then?

Mark S · 13-03-13, 05:36 PM

I think its a momentary contact rather than a switch, so you would need a little switching circuit behind it.#

Is it not easier to wire up a relay on the wires that go from the BCU to the rear heated screen?

petet16 · 13-03-13, 05:43 PM

I had considered linking in to the hrw wires from the bcu to switch a relay, I'm just a bit concerned about how temperamental the bcu can be.

The switch would have to be used with a latching relay because as you say it is a momentary switch, so press it once to latch the relay, and again to unlatch.

Smokey · 13-03-13, 05:58 PM

Momentary Switch for sure.

4 wires, Black, Red/Black, Yellow/White and Yellow/Blue

Black - Common
Yellow/White is Normally Open
Yellow/Blue is a +ve voltage for Tell-Tale light
Red/Black is +ve voltage for the light

Hope this helps?

petet16 · 13-03-13, 06:25 PM

Cheers Smokey that's a big help, it confirms that the mk1 wiring diagram is the same as the mk 2 for the heated rear window, ideally I want to make the front screen work with the rear so that they're both on a timed cycle.

Smokey · 13-03-13, 06:27 PM

So only having one switch? Surely that would be the easiest way to go?

petet16 · 13-03-13, 06:32 PM

Yes, just the rear screen switch, and use the +ve feed to the hrw element to switch a relay for the front screen, Then just source a live feed for the front screen element, the easiest way to do that is by using one of the spare connections on the fuse box in the cabin

Smokey · 13-03-13, 06:35 PM

Sounds like a plan. Shame you are getting the screen just as the warm weather is appearing. Will be an awesome mod come the frosty mornings though!

petet16 · 13-03-13, 06:38 PM

lol yeah tell me about it, the plan was for them to be ready last year, but it took forever to get enough people for the group buy.