Does anyone know the procedure to replace and install a new turn signal repeater cancelling plastic guide on the upper steering column (on the steering shaft itself) on the W124 model? Do I need to detach the upper steering column from the lower column to aid installation?

Alex

never did a 124 but on a 126 you remove the steering wheel, cruise switch, and then the turn switch. If it's not canceling most likely the plastic tab broke on the switch, about $125.
jerryb