SC ignition key issue question help appreciated

[keyla]

I have a 1981 911 SC and there is a problem with the ignition switch. The key turns and unlocks the wheel but it will not activate to start mode to start the car. It seems to not get to the start spring - release mode to activate the starter motor. It does not start or run.
Any help pointing to problem and the correct solution. Would it be the electrical part on the rear of the assembly ? Any pointers on the procedure.
Thank you.

[smadsen]

If the key won't turn all the way to "start," try a little graphite dust or some other lubricant then wiggle the key up down, side to side, in to out. If it starts, it's the key mechanism.

If the key goes into the "start" mode (full right against the spring) and still no joy, start with the easy stuff, fuses, battery, ground straps. Then dig into the switch & wires behind the key mechanism. After that, you're pretty much down to the solenoid/starter.

[tirwin]

You can also detach the electrical part from the mechanical part of the switch. Stick a screwdriver in the female side and twist. If the car starts then the mechanical part of the switch has failed. Could be worn switch. There are a few threads that discuss potential fixes. I didn’t have any luck with mine. Had to replace the whole ignition lock assembly.

[tirwin]

It’s been a long time since I did this. I remember I took the driver’s seat out and a lot of swearing.

Here’s a thread that may help:
Ignition switch repair and Anatomy questions

Just try to remove the electrical part first. I think there is a single bolt. Once it is removed you can separate the electrical part and test it with the screwdriver method. If it works ok then it’s the mechanical side of the switch.

If mechanical then I think the whole ignition lock assembly has to come out. There are two sheer bolts that have to be drilled out. I’m sure there are good write-ups on it.

[keyla]

ALL SET! Thanks to all, seller located secret proper key... Vrooom !

[Coastr]

The tab that transmits the key twist torque to the electrical switch is a known weak spot. The symptom of it breaking is as you described - unlocks wheel but doesn’t engage starter. While it sounds like you got it to work with a different key , beware, the mechanical part of the lock costs about $1000 if you can find one. But you can fix with a dremel, some Alu and job weld. You know it’s broken when you take the switch off the back and a small piece of metal falls out.