'86 300E - Ignition Switch Problem

[Phalcon51]

My ignition switch just died today leaving me stranded in the parking structure at work. I noticed earlier today on several occasions when I started it that when turned all the way CW against the spring, it would hesitate for a second before the starter would begin to spin.

When I went to leave after work, the key would turn, the dash lights would come on, but I couldn't turn it to where I could feel the return spring, it would just stop solid and there was no hint of turning tyhe starter motor. After trying several times and taking the key in and out and locking/unlocking the steering wheel, suddenly the key turned noticeably easier (as if something had let go) and only one red dash light came on, and wouldn't go off before turning the key back and forth a few times. Now, the key turns easily about a 1/4 turn, no dash lights come on, and of course the starter still doesn't spin.

Can anyone hazard a guess whether this is likely the lock cylinder or the switch itself, or maybe even the intermediate shaft in the housing?

I need to come back down early tomorrow on my motorcycle with some tools and try to get it apart. What tools do I need to get at and remove both?

The car has about 110K on it; should I just go ahead and replace both?

Thanks for any help

Gary

[Ashman]

do a search on ignition switch and see what you come up with, many have had similar problems and have replaced the internals without the actual switch, and others have had to replace the whole switch too.

Alon

[Phalcon51]

I did some searching and found this info. Hopefully, it will save someone else a little time.

If you click on this link:

Help! Newbie has Tumbler Problem

you'll find a drawing of the tool needed to remove the tumbler assembly.

Anyone know what actually breaks, typically?

Once I have the tumbler out, can I turn the switch? What will i need, screwdriver or pliers?

Gary

[Phalcon51]

Does anybody know where on the Service CD I can find any info on removing/replacing the ignition switch parts? I've been looking all over them and I can't find anything.

Thanks

[stevebfl]

You probably need the steering lock the shaft the carries the rotation from the tumbler to the switch collapses (its a tube) and eventually there is no coupling.

The instruction are in group 46 of the service manual.

[Phalcon51]

Thanks Steve, you're right on the mark.

On my way in to work today, I stopped at the dealer to have a look at the various parts. While looking at the part of the intermediate shaft in the steering lock housing that couples with the switch, my first reaction was how spindly it looked. Sure enough, when I got to the car and removed the tumbler/steering lock/switch assembly, it was the spindly part that broke. There were several little crumbled up bits that fell out when I removed the switch.

In your experience, is there increased resistance to turning in the switch, over time, that puts extra load on the shaft turning it, or is it just inadequate engineering of the shaft itself? I'm wondering if I should replace the switch as well as long as I'm in there.

Also, do you know any way of strengthening or reinforcing the shaft to prevent it from happening again?

Thanks for your help

Gary

[stevebfl]

It breaks, but it takes time. I don't think the electrical part causes it, but they are cheap (the electrical switch) and do have problems occasionally.

I wouldn't worry about strengthening it. It lasted 16 years. The new one will probably do better; the luck of the draw.