You may be able to find a wiring diagram online for the W124 or you may have to get a workshop manual; which has all the diagrams and torque specs. In case you're going to be doing any other work on your MB, take a look at the link below to our site's DIY tech articles on various components!

Mercedes-Benz E-Class W124 (1987-1995) Technical Articles - 300TE 24, 300CE 24, 300E 24, 300CE, 280E, 300E2.8, E280, 320TE, E320 - Pelican Parts