My 300SD let me down the other day. It would not start. The battery is good and fully charged. It appears to me that either the switch/key or the starter is bad. When you turn the key to glow the plugs the light works normally but then when your then turn the key to the start position nothing happens. No clicking or sound at all. I had to have the car towed back to the house. How do I diagnosis the problem?

__________________

• 2001 E320

Try Neutral gear selection , if auto trans.
Hold key in start position while moving shift lever around N position..if NSS is at fault, it can be adjusted..

There should be a place under the hood where you can jump the wires and check the starter. On 123's it's on the passenger inner fender well.
You can also search on key switch problems. There have been a lot of reports of problems. Try holding the key in the start position for a while. People report it can take a number of seconds before the starter engages. One forum member traced the problem down to worn and dirty contacts in the switch.
The problem could also be a poor connection somewhere in the wiring.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Follow the positive battery lead to the starter. Back from the starterpositive terminal another wire goes to the passenger side ubove fenderwell terminal block. There is also a small wire comin from start circuit to another terminal next to it and going back down to the solenoid. Make a jumper wire and bring tweelve volts to the small terminal. Solenoid may be stuck. Asolenoid is a coil that becomes magnetized and pulls in a plunger which engages pinion gear and finally switches high current twelve volts for the starting circuit. If it failsto pull in all the way it is bad. If nothing happens but possibly dimming of the interior lights. You may take a set of jumper cables place one on the bare braided cable on top of the starter and other to positive battery. See if you can bump the staerter. There will be sparks! If starter spins it is solenoid. I have only found one place on the net to get solenoids. All car parts has new made in Germany bosch solenoids for 27.00. Alot better than a starter.

Thanks for the feedback. I will check into the starter. How do I remove the key switch so that I can check it out?

__________________

• 2001 E320