The CD manual says that in an 84 SD, the following items run off fuse 15:

- power seats
- warning module
- courtesy lights
- antenna
- alarm

The warning module is above the brake pedal beside the cruise amplifier. Thomaspin's website has good pictures of this area.

Check for current draw with the alarm module and warning module disconnected. I suppose you should check the power seats as well.

I think the safety belt handover arm is the device in an SEC that offers the seat belt tang to the front occupants when they close their doors. Obviously not present in your car.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD