Problem with lights.
 

I have just had to replace the heater matrix on my 2.0T V40. As I am sure you all know this means removing the entire dashboard and heater box.
I worked my way through all this, replace a leaky matrix and methodically re-assembled everything.
Re-connect the battery and turned the key, engine fires up and runs smooth, heater and climate control seem just fine, no leaks. Then I notice the left hand indicators are on, not flashing but on solid. play with the lights and indicator stalk and the left hand stays on along with the headlamps and the tail lamps in the hatch but not the ones in the car body. The gauges in the dash don't work either nor do any of the warning lights, unless you pull the head lamp flash lever then some warning lights come on and the led display comes on for a minute or so then goes off again.
Is this a failed CEM? I have checked I have plugged everything back in correctly, even sprayed with contact cleaner.

The solid indicator could be a dry (sticking) relay but not sure this would adversely affect any other lights!

To me it sounds like a bad negative connection.You can have the most weird things happens.

Yes a bad (or missed) earth gets my vote too, it can cause all kinds of weirdness.

That makes sense, seen weird earth related things before. There was only one earth connection I recall removing, it goes onto the metal frame behind the radio and heater controls.
I remember re-fitting the earth bolt and connector, but have my doubts about where the frame mounts to the trans tunnel, there was a bit of light corrosion and dirt around the mounting bolts, and the passenger side had gotten wet after the coolant escaped out the heater box.
Will check them out tomorrow after work and report back.

Checked the earth leads behind the radio, clean and tight and checks out on my continuity tester as ok, battery earths are all good.
Are there any earth points around the CEM unit?