http://www.slkworld.com/165914-post13.html

 

Many thanks for that. The under the bonnet list is the same as the one in the lid of the fuse box, a quick look at the dash list shows different values of fuse, but does show a fuse 4 as a turn signal lamp, so I will have a proper look in the morning.
I did take this at the start to a Mercedes specialist not far from where I live showing him the fault and asking about the fuse, but he put the test box on it and said it looked very odd, then advised I bring it in for repair and investigation, but when he started talking many hundreds of pounds i decided I would have a go myself first.
He did not look at the fuse box in the dash, so if it is a fuse there, I will go back and tell him, possibly even kick him in the shin, well maybe not.

 

If the emergency flashers are working, the CCM is OK.

 

Thanks for that, could have saved some money, but eventually I will sell the one I bought on Ebay.
The Mercedes "specialist" thought that was the problem initially, and put another in that he said had a different fault on, which would at least prove something. The fault stayed the same, but as I left he changed his mind and said it was not definitive, and it could cost £700 to put a used one in.
I find the SLK hard to fault find on, but it is a great car, I just wish I was as agile as I used to be. After lying on the car floor all afternoon yesterday, my wife had to get me out with a can opener :wink:
Anyway, I will carry on, now I at least know the fuse is in the dash fuse box, so if I can find the source of the low voltage I may crack it yet.
It is a pity the main dealer is so very expensive, where I live, £150+ per hour, and works to module level, so very expensive.
Kind regards, Brian

 

Have you tested the function of the switch down line of the connector? If your hazards work and the switch work, the connector is what I would check next.

 

Well, I checked the voltages on the fuses attached to the light switch, jbanks15 kindly sent a link showing the fuse was on the dash, (though the fuse positions seem different).

Presto, low varying voltage on the first 15 amp fuse I tested, also on another 15 amp fuse, (not sure which is which but at this point but academic, as, though I have a cold, i was in very close proximity to the unit, which was hanging down, and noticed a very faint smell :surprise:
Further inspection on the rear when I turned it over to check the connectors, burnt plastic, a hole right through.
I disconnected the connectors, no sign of overheating on them, and prised the lower cover up, and low and behold, burning, right through the pcb? onto which the long switch connectors attach.
I have not figured yet how to get the plastic cover off, but it looks bad, I have no idea how it only affected the indicators, seems amazing the lights worked at all.
Researching now for a replacement, part number 170 545 05 04, I have found what might be the one on Ebay and have emailed him to try and ensure it is OK.
I will keep you posted, and will hopefully have some pics which might help others.

 

Ordered the part from a breaker up in Scotland, should be here in a few days. The copper tracks are on a thin flexible insulator that wraps around the switch cover, the "erosion" has removed portions of the copper and the insulator. I will disassemble it further when the replacement arrives.
There is a sticky smelly deposit mixed with the carbon formed which conducts, and has flowed between the film and the fuses, yet none of the fuses were in fact blown!.

 

Interesting - which fuses showed low voltages, and how exactly were you measuring (meter lead placement?)

 

All measurements were from a good chassis ground, to the point under test. I was looking for low varying voltage as found on the connector to the multi function stalk switch. I first probed on fuse 11 because it was 15 amp, the size of the fuse I was looking for, and found the voltage on each side of the fuse changing variably from about 6 volts to as high as 10, tried it on fuse 9, another 15 amp on my car, which was the same as fuse 11, and fuse 10 had zero volts either end. I was holding the module in my hand still connected, and then I noticed the smell, and as soon as I moved it a bit I saw what looked like a blob at the back underneath below the plugs, and touching it disintegrated leaving a hole. I removed the switch altogether, and saw about a half inch circle clearly burnt, with discoloration all around it. I have taken some pictures which show pretty extensive burning around the rear end of the switch, amazing no fuses were blown and so much worked OK.
I have taken the cover of completely, (finding out how the knob came off was a challenge), and cleaned it, but it looks beyond a stable repair. I will dismantle it completely at some point, and post the pictures once I have sussed that out. There is a sticky brown substance on the plastic around the area, I wonder if it has been sprayed with something at some time?

 

New switch arrived this morning, fitted, and all super OK. Really pleased, and it all went back together easier than it was to take it apart.
My SLK is once again my best friend and super toy :laugh:

 

Well done Yozzer, saved yourself a wad of cash and learnt something in the bargain, bonus is you shared it on here for the benefit of others.

 

yosser,can you post those pics as I seem to have the same problem,and a laymans explanation,as i'm a bit of a novice when it comes to electrics
thanks

 

Hi, I have replied to your PM, (unable to send a proper PM as I only had 14 posts, but this makes it 15, so if you get stuck I can now reply. Just be aware, it was the light switch on the dash to the right of the driver, (UK model).
As I mentioned in my PM, I am 75, so the real hard part was getting down under the steering column, the second hardest part was getting out again!
Best of luck, just check the voltages on the fuse I mentioned earlier in the thread, that will help confirm it is the same problem, or the fuse may be gone.

 

ahhhh,light switch,i thought you meant the stalk switch on the column:wink:will look tomorrow..thanks

 

Hey @Yozzer8 - great post, really informative. Glad to see someone who isn't afraid to 'get down and dirty' to solve a problem. Well done.

 

took out the switch the following day,all looked ok,but couldn't test fose voltage as my tester gone kaput,even disassembled it and all the pc boards looked clean and complete,but they are Very small!decided to order another switch anyway as I didn't know where to go next.switch arrived today....from Estonia!!(must have come by mule train) fitted with difficulty as I had my fingers crossed,but...........it WORKS:grin:
big thanks to Yozzer Silky is back on the road!!

 

Really pleased, having looked around the internet at the time I had the problem, I did keep coming across people with the same problem, but no fix. I suspect there are a few SLK,s driving around without indicators! Well done! Just wish I could fix gas boilers, came back from holiday and one of my son,s who was looking after our house called in and smelt gas, and the emergency gas guy came and turned off the gas to the house. Middle of winter in the UK, so the house was like a fridge. Just been fixed, gas boiler had gone west, and with all the new regulations we had to basically have a new central heating system in, cost a fortune. Ah well the SLK is still running fine.
Keep trucking ;0)
Brian