No Ignition unless I jiggle the gear shift lever
 

I have a problem developing with my '92 SL500. When I turn the key, the instrument panel lights up but the engine won't start until after I jiggle the gear shift lever in Park. What am I looking at?

maybe the neutral safety switch on the side of the tranny. they are about $60 online. a cheap try. they may have a trick lock ring on the wire connector. otherwise a couple of bolts to remove. will it start in any other positions? it's not supposed to.

It'll start in neutral.

but not in any of the drive positions or reverse? do you still have to giggle in neutral or just in park? still, I don't know what else it could be other than that switch, or a bad connection at the switch. I don't think if there could be a problem in the shift linkage.

Do you here the linkage rattle when put in park or in gear. If both shift bushings are missing you may not be going all the way in park. The shifter should feel fairly tight not loose. Check this first. The bushings are only a couple of $ and not that hard to change.

I had the lower bushing break out on my slk and it caused a rattle type vibration under a load or slight excelleration around 2 thousand rpm. If I kicked in the passing gear, the supercharger, or let off on the gas it would go away. It had no effect on the tightness of my shifter or shifting, just the linkage rattling, but again I only lost the one.. I know the bushing is a common problem on the early 170 slk. I never realized or heard it could be a problem on the 129sl too...?? learn something new everyday. probably the next thing to do is jack her up and have look-see under there to see if something seems loose or missing

Up untill the 220 most modles used the same bushings. Some last longer than orhers due to exhaust location, Be sure to check the bushing on the trans as well. If both are gone then you could have starting issues. I have even seen the linkage fall out.

It needed a new neutral safety switch. Thanks everyone, for the replies.