'84 300SD won't even try to turn over
 

1984 300SD approx. 350,000 mi recently rebuilt alternator due to constant battery drain, replaced voltage regulator, recharged battery, now it won't even try to turn over. when i turn the ignition, there is absolute silence. all lights/electronics work perfectly. any help provided would be most welcome.

Do you hear the starter solenoid click when the key is turned?

If not try moving the tranny selector to N then back to P. Could be a neutral safety switch. Also, check your fuses. I do not know which number for the starter solenoid, though.

If you hear the starter solenoid click, the your starter could be out.

or you could try tapping on the starter with a lug wrench or a hammer, just one or two should do the trick, then try to start it again. sometimes it works, sometimes it does not.

First, confirm your battery is really good and charged. Then make sure all connections are clean and tight and inspect battery cables... are they old and possibly corroded within the insulation? If so, there could be too much resistance to allow necessary current to the starter.

However, your description indicates the starter solenoid switch may be binding and stuck or perhaps worn out... just pull the starter and take it to the alternator/starter/motor rewinding shop or local Parts place to check and repair it.

Don't laugh but you may be able to jar the switch into operating by firmly tapping on the solenoid housing with a wrench or small hammer from underneath the vehicle while a helper turns the ignition key. Yes, it is dangerous so I don't reccommend that unless you are stuck in the middle of nowhere and simply have no other alternative but to try jarring it loose... you have to make darn certain the brakes are set, tires chocked, and your body parts and clothing are clear from the moving parts etcetera, etcetera.

No...just pull the starter and take it to the alternator/starter/motor rewinding shop. Consider replacing the battery cables while you are in up to your elbows anyway

Good luck and motor on

Before spending a bunch of $$$'s.......
 

Check your grounds, especially the engine-chassis ground strap near the starter.