68 key warning buzzer-ignition switch tiny brass contact

[Roger O.]

Inside the 68 ignition switch at the bottom is a tiny brass contact that when grounded sounds the key buzzer. After removing the key tumbler I use a screwdriver to return the switch to the actual ACC or Off position , now pushing the tiny brass contact the buzzer will sound - so I'm good from there, clear through the door jamb switch.
Here is my problem the little black plunger coming from the key tumbler that pushes on the tiny brass contact is constantly spring loaded. Shouldn't this black plunger be "unsprung" and only have force on it when the key is fully inserted in the tumbler ?
Thanks

[Jack H.]

Re: 68 key warning buzzer-ignition switch tiny brass contact

Yes, the black plunger should be 'unloaded' when the key is removed such that the force of the brass contact will push it up when the key is withdrawn. I see two issues...

(1) The innards of the lock cylinder can accumulate dirt/grease from prior use (insertion of key shanks over time) making the black plastic plunger 'sticky'. Try shooting the keyway of the lock cylinder with solvent, like carb cleaner, and blowing it out with compressed air. You'll know when you've got it right--you should be able to push the black plastic plunger up/into the lock cylinder with almost NO force.

(2) The brass contact in the lock may have taken a 'set' causing it NOT to exert as much upward force as it did when it was fresh/new. A TINY amount of 'adjustment' could be enough to restore its original return force.

Note: if you execute #1, consider a 'puff' of dry graphite lube into the lock cylinder when you're done with the clean-up. You WANT the keyway, lock tumblers and springs to be nicely lubricated and the clean-up process will remove most/all of any original lubricant that was inside...

[Roger O.]

Re: 68 key warning buzzer-ignition switch tiny brass contact

Thanks Jack. The plunger is very free but has a pretty strong spring behind it.
In this pic is the black plunger forced out by a spring. Using my calipers I measured from the brass contact to the top of the switch. I figure once the tumbler is in the switch (with no key ) the black plunger should only stick out about 1/8" (but be free not under spring tension),once the key is inserted the plunger should move out an additional 1/32" closing the circuit via the brass contact at the bottom of the switch.
I can push the black plunger in to the 1/8" out spot I think it should be but its not easy and it pops right back out.
I feel if I removed the spring from behind the plunger this switch will work fine.

[Roger O.]

Re: 68 key warning buzzer-ignition switch tiny brass contact

Here is a picture of where I think the plunger needs to be , notice the dent in my finger from the spring pressure. Just want to clarify , in the pic above with key inserted the key is not forcing the plunger out. If the key is out the plunger is still out to that point. Sorry about the focus.Thanks for any info provided !

[Roger O.]

Re: 68 key warning buzzer-ignition switch tiny brass contact

OK mystery is over , I got it figured out.

[Roger O.]

Re: 68 key warning buzzer-ignition switch tiny brass contact

I have it figured out I think. I was just going to put a new cylinder in but the lock shop says the new ones on the shelf are just like what I have.
If this is so and I'm correct in the way I think it should work the lock shops new ones have been assembled wrong.
Could someone that has a working key buzzer pop their lock cylinder out and tell me if theirs is sticking out this far ? Thanks

[Roger O.]

Re: 68 key warning buzzer-ignition switch tiny brass contact

Any input would be appreciated.

EDIT-Got it fixed and back in the car and it works great. Surgery was required !!!