I am having an odd problem with a low mileage 1994 SL500 I just purchased. The turn signals for either direction flash very rapidly, as if a bulb has failed, and the bulb failure light on the dash comes on when I use either signal. All four bulbs (front/back, left/right) have been replaced with new. And independant shop gave up and said it was "probably" the combination relay, but at $425 I'm looking for something more convincing than that. Since that relay also controls the wipers and rear defrost and both of those are working flawlessly, I'm skeptical of that direction. Any help would be greatly appreciated. Thanks![/align]

 

Althoough I have not seen the wiring diagram, perhaps the simplest common sense thing I can think of is to run an external ground to the metal base of an affected bulb, and see if your problem goes away. Just grasping, but I get lucky once in a while.

 

Being new to the SL series, my guess without looking at my 98 would be a burned fuse. The problem you describe is common to both sides. I recently had 1 bad RR bulb with the same symptoms. And not having access to the wiring schematic, you may have a poor ground somewhere, or a power (voltage) supply to the lamps common to both sides when the turn signal switch is in either position. I doubt that you'd lose grounds on all four corners as well. Do any of the external lamps flash, and what type of pattern is there, i.e. both fronts or both rear, left only, etc.

 

I'm having the same issues with my turn signals, only they work intermittently. However, my wiper and rear defrost are affected as well. Has anyone ever put in a combination relay?

 

assuming you replaced all the bulbs with "oem" bulbs, the module is located in the drivers side fuse box at the back of the engine compartment. there are 5 relays and three modules. it's the medium sized one in the middle toward the front of the car. those are very dependable so try to find a used one online, starting with ebay. If you go new, try shopping several dealers. as far as part of a module failing, that is typical. Especially the top controller. avoid jump starts and operating with low or bad batteries. don't charge w/o disconnecting the battery. pulling the ground will suffice.