C180 flashing heater lights,keep flashing untill you turn side lights on. also heater is blowing hot all the time even when turned to cold
Has anyone has this problem, can you help. thanks. john.

 

I am interested to know if John Marsland had a succesful reply to his car's problem - I have exactly the same with mine, a 1994 C180,
I already have had 2 differing provisional diagnosis - 1) faulty heater swich unit on the centre console ( auto electrician) and 2) faulty duo valves (Mercedes dealership). if either of these two items could fail and cause the constant hot air, why the flashing heater switch panel lights,
and why does the flashing stop when the side/head light circuits are on?
Also the air recycling swich does not light up / work.
To have so many unrelated things go wrong usually suggests an earthing problem.
Any suggestions will be much appreciated.
Tony B-S

 

let me know too...............got the same going on on my 94 c220. the centre flap blows cold. the recirc light flashes if you hold your finger on it when the panel is flashing, and I noticed it flashing about once a minute anyway.

seen a few posts on it but no solutions. tried messaging the posters but no reply so far.

have a small hissing sound when i let off the throttle, but had that in every mb I ever had...........

am planning on removing the facia and controls and having a look, cleaning up any contacts I come across in the process.

please post if you solve it, or anyone who's had this before and solved it - when it gets hot in the summer it will be awful!!

 

flashing stopping occasionally at the moment - suspect a loose electrical connection.

also linked - the odometer light flashes when headlights are on unless rheostat turned full up.

mainly posting this to push it back up to the top as no-one seems to be responding to this or my other poston the matter

 

Ive tracked down the solution - it was the heater control 'black box' unit with the two rotary ***** that was at fault and causing the strange console lighting activity and the temperature running constantly on hot. A pre-used unit (£25) from a Breaker Link supplier took 30 minutes to get in place and works perfectly.
Tony B-S