Had a problem for a few months now which I have now solved and want to share with others because someone will no doubt encounter this in future or have done so in the past but there is little info after days even weeks of searching on here and externally the net.

Initially, I had a problem with the indicators (turn signals) not working. This issue would happen randomly and then suddenly remedy itself with no apparent reason or situation. This was a livable bug-bear and I just put up with it for a while. With this error, a bulb out warning light would appear and you do not hear the clicking nor see the green arrows flashing on the dash.

After a few months the problem worsened and became a pain in the neck (more frequent), however, by chance, I realized that if you applied pressure to the light switch on the dash, the indicator lights would start to work again. Bizarre but now a livable annoyance again.

Next few weeks, another problem surfaced as I noticed a bulb out warning light and found my drivers light headlight was not working. Thinking it was a blown bulb I changed the bulb, but the problem remained. I was a little stumped and left the issue for a few days to ponder (it was light nights anyway).

After a few days however another new problem surfaced - this time a new warning light – the BAS / ESP light in addition to a bulb out light again (even in the day with no lights on the bulb out light would appear). I checked the whole car, plate lights, sidelights, repeaters etc but all ok. I put it down to the problem with the headlight and planned to get the car looked at.

After a week or so of thinking I had a bad apple of a car not to mention doing quite a lot of motorway driving that week, I realized one evening that the light out bulb was actually on because the brake lights were not functioning, at all. Quite scary to think what could have happened on a motorway.

My first thought was the fuses might have gone, so I undid the cover on the drivers’ side dash and took out the relative fuses for brake lights, indicators, and headlights, gave the box a quick spray of compressed air and replaced them.. and HayPresto problem solved, or so I thought.

I went a couple of weeks without any errors until one day out of the blue, everything failed miserably again and all the warning lights came back on the dash and the brake lights stopped working. This time no amount of fuse swapping was working so I parked the car up and started ringing round for advice after finding little on the net. I started off by ringing Chrysler but sadly their advice was of little to no use as I appeared to know more than they did about the Crossfire.

I then rang a number of independent Merc garages most of whom suggested 2 problems – 1 the light control switch and a separate issue causing the ESP/BAS light. A separate Chrysler garage also concurred with this in saying that the two systems were completely autonomous.

I was a bit bullish and disagreed with their professional opinions (only because I had personally witnessed the temporary fix of all the errors through the fuse replacement and applying pressure to the light switch earlier), and told myself that this HAD to all be related to the same problem.

So, Instead of spending lots of time and money on a diagnosis I decided to order the light control switch which also houses the fuses as one part. This cost £250.00 new. I then asked the dealer to not try to diagnose my problem, just fit the part and let me worry about the consequences it if it did not solve the problem.]I am happy to say that this has completely resolved all of the above issues. Chrysler actually had a former Mercedes mechanic in the garage and he suggested that my diagnosis was indeed correct. Apparently, the light control switch and BAS / ESP system are indeed autonomous, however brake light failure is seen as a fault by the BAS system hence reports it by illuminating the light on the dash. The light switch was causing the failure hence when changed all resolved.
Total cost £318.00 – not bad when you consider what you could have spent on labour to incorrectly diagnose a problem.

 

The light switch/fuse unit you changed is a known problem component. I had mine changed under warranty at 17K miles (2 yrs ago) I had intermittent headlight problems and playing around with the fuses did temp fix it, but I took it in and they said immediately what the cause was and changed it FOC. It also would be repairable if need be by removing. The issue is caused by bad earthing and shorting.

 

The light switch/fuse unit you changed is a known problem component. I had mine changed under warranty at 17K miles (2 yrs ago) I had intermittent headlight problems and playing around with the fuses did temp fix it, but I took it in and they said immediately what the cause was and changed it FOC. It also would be repairable if need be by removing. The issue is caused by bad earthing and shorting. Apparently it was a known SLK320 issue and many SLK's had theirs changed while in warranty

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Interesting Steve as some of the the merc garages I rang had never seen the issue before and some had. The annoyance was that almost all of them were adamant that the BAS/ESP light and subsequent brake light failure were seperate issues to the headlight failures.

I could have been in for a hefty diagnosis bill if I didn't have my wits about me.