The full set of W126 service manuals is
- The W216 chassis & body manual.
early ones are 2 volume; later ones are a big single one
- The engine manual for your vehicle. Plenty to choose from
- Climate Control manual
- ETM (Electrial troubleshooting manual) for your vehicle.
It's the schematic laid out as a "current flow diagram"; a map for your multi-meter.
- TDM (Technical Data Manual) that covers your model year. They come out every three years or so. This book is all the tables of guides for world models.
- The owner's manual (yess, this is classified as a service book; have you read yours?)
- The glovebox parts book
-CTH