UPDATE: partially solved: Heater blowing hot air only and flickering rear side lights

[Remithevan]

Hi all as per the title really, juat picked up my 2011 Enterprise van and seems the side light at the rear flickers as does the door brake light. 

And the heater just blows hot air?

Im new to citreons so can anyone advise where to start poking around?

--- EDIT ---

OK so I fixed the heating, turns out the cable had kinked and flicked around the arm that moves, popped it around all works great cold air, hot air and everywhere in between.

So the Light issue, When the side lights are on the left flickers and I also noticed the brake light is not working on that side either, cleaned the connections etc,  swapped bulbs with the other side, same problem.

I noticed when I open any of the doors it stops? ( brake light still not working on the left/near side ) so its a total head scratch to be honest... I'm getting close to just getting and Auto electrician out to take a look.