SLK Turn Signal Problem
 

We have a '98 SLK230 and the turn signal blinker stops working after a while and then goes back to working after the car cools down. What happens is that when you use the turn signal after driving and have been using them for a while, specially on a warm day, it stops blinking. The light comes on the dash display and outside, front and back, no bulbs are out. Most cars have an easy to replace relay for this under the dash but not this car. When it works, there's a ticking you can hear/feel in the back of the fuse box in the engine compartment. Allegedly, there's a module that needs replacing. Does anyone know if this is a DIY project and what part I need to replace?

That car uses a "combination" control unit to operate the blinkers..try to find a USED one from re-cycler...a NEW one is $$$$ & requires coding by MB..

Trying to figure out which part this is by searching parts catalogs. The closest in description I could find is Dash Control Unit, SLK230 (Hvac- Control - dash control unit). $482 MSRP price, $361 discount price. Is that the one?

MB part number is 170-820-09-26...earlier number was 170-820-07-26

Thanks for the info, it's been very helpful but OMG!, that part lists for $790 for a blinker relay, ouch. I checked with my online parts place Duval Motors and it says it's for the hazard/blinker and they discount it to just under $600. Ordered it from a salvage yard for $125. He said it's a theft module but I asked him to doublecheck the part number and he said it's 170-820-09-26, so I'll have it next week.

Where is it? Here's a pic of the fusebox area, is it here? The ticking from the blinker relay seems to eminate from here.

http://www.detali.ru/cat/MB/B54045000124.0715.gif

The actual computer is on the other side...sound is generated by the inst cluster.

Thanks for you help. I bought the module from a salvage yard for $125 and it worked.