smparr

My 1990 CC ignition lock will not turn back to ACCY. It does start and run positions just fine most of the time. Sometimes it's a little finicky, but it will not unlock to Accessory. It is the original square head key and the copies I made don't work in Accessory either. I've had it for two years and this has never worked. Any ideas?

Sugar Bear

Unbolt the ignition switch to rule out it being seized and that the rod to the switch is free. It is on top of the steering column.

Good luck!!!

smparr

I was just able to wiggle the key and get it to occasionally go to accessory after oiling the key. I'm beginning to think the key is just that worn out.

Sugar Bear

It may be the key. If you have the key knockouts with the codes on them or just have the codes have new ones made by the codes.

Good luck!!!

no1oldsfan

Worn out key will not touch all that it should. Keys made off a worn out key will amplify the worn key. The points may not be as strong as they need to be. Like Sugar Bear said if you have the key number stamped on that key I go with that. New key could solve all your issues.

Hammerdrop

In the hardware store business, we used to regularly raise the old worn out keys with a couple thickness of paper as it was put into the machine. That would result with the new key teeth being slightly higher than the old key. This trick worked many a time. Workers today might not have had that trick handed down to them.

Jeff Stout

Any locksmith should be able to read your key cuts by sight and cut a key to factory specs. If you sent me a picture of key I should be able to do it. I have a feeling your gear assembly behind key cylinder is bad.

smparr

I don't have the punch outs. Is there another way to find the codes?

Sugar Bear

Sometime they are handwritten in the owners manuals or on other documents at the time of delivery. Look for a 4 character handwritten sequence containing #'s and letters.

smparr

No such luck. Can you use the VIN to get them?

Sugar Bear

They could be retrieved by VIN years ago. I don't know if GM might have the info available through their remaining product lines. A CO member will probably know that answer and chime in.

As suggested by other members a locksmith may be able to help. The paper under the key being copied is definitely worth a try.

Good luck!!!
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69HO43

If your keys are worn, likely the cylinder is toast as well. Fix it for $25 for a GOOD long time. GM p/n 7830380. Superseded to 19356477. Fit's all 1990 B-body columns tilt, non-tilt, whatever.
Comes with 2 new GM square-head keys WITH the punch out codes to save for later in case you need it. Pop the steering wheel, take out the bolt, pull cylinder and replace. Unless you have another lock somewhere that requires the square head (usually they don't), you can replace the keys and lock without issue to your car, functionally, anyway.

Fairly simple IMO. With the right tools, you're done in 1/2 hour if you've never done it before. First, disconnect battery. IIRC, the tools you'll need is whatever fasteners holding the horn pad on your wheel, if any. Need a steering wheel puller and a lock plate compressor to get the snap ring off the shaft. Phillips head for turn signal and the cancel cam, plus the appropriate sized torx screwdriver for the cylinder hold down screw. The puller and lock plate compressor could be borrowed from Advance Auto parts or some parts stores near you may provide loaner tools if you don't have the "special tools" to access the screws. Someone correct me if I'm wrong here.

7830380 NOS GM CHROME IGNITION LOCK ASSEMBLY WITH KEYS OEM Original Equipment | eBay

Here's a video of replacing one if you haven't done it before. It's on an 89 S-10, but the same parts apply here. There's a bunch of them on youtube, so pick one and go.