Already frustrated with the W124 head gasket issue, I now have a problem with the top operation on my W208.

The rollbar light flashes after starting the vehicle, and toggling the switch gets no up/down behavior from the rollbar/rear headrests. I can hear a "click" when the switch is actuated, but that's it.

With the rollbar inoperative, the soft top operation is halted beyond the windows lowering when the front of the top is unlatched. The top lowering switch just flashes slowly.

I believe the inactive rollbar mechanism has something to do with this. Are there any tips/tricks to troubleshooting this w/o specialized diagnostics?

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car