C3 door locks & ignition switch & keys

[Gary B.]

Can anyone tell me what year in the C3 era the door locks and ignition switch were no longer operated by the same key?

Thanks,

Gary

[John M.]

Re: C3 door locks & ignition switch & keys

My '74 uses the round key for the doors and alarm, and the square key for the ignition. Hope this helps!

John

[Jack H.]

Re: C3 door locks & ignition switch & keys

Use of single key ended in 1964. The '65 and up cars used two keys...

[Jim T.]

Re: C3 door locks & ignition switch & keys

My 68 and 70 use the same key for the door locks and ignition.

[Jack H.]

Re: C3 door locks & ignition switch & keys

Yeah, but the car uses (or should be so equipped) with a second key to operate the glove box (rear compartment) and the spare tire lock! That's what's refered to as a 2-key car...

Up through 1964, all Chevy's (including Corvette) used one key to operate ALL locks on the car. I think that's what the original post was asking...when was the transition from a 1-key to 2-key car made.

[Gary B.]

No, I wasn't asking about 1 vs 2-key cars

Jack,

I actually wasn't asking about 1-key vs. 2-key cars. I know that changed with the 65 model year. Rather I was asking when the door key stopped being the same as the ignition key. Based on Jim's reply, in 1970 the door key and ignition keys were the same, but by 1974 the door key was the round key and the ignition key was the rectangular key. When did that trend start?, i.e., what year between 1970 and 1974?

Gary

[Kenneth T.]

Re: No, I wasn't asking about 1 vs 2-key cars

Jack,

I actually wasn't asking about 1-key vs. 2-key cars. I know that changed with the 65 model year. Rather I was asking when the door key stopped being the same as the ignition key. Based on Jim's reply, in 1970 the door key and ignition keys were the same, but by 1974 the door key was the round key and the ignition key was the rectangular key. When did that trend start?, i.e., what year between 1970 and 1974?

Gary

Gary,

My 71 uses a A (square head) key for the doors and ignition and B type (rounded) for the glove box, alarm and spare, as Jack stated.

[Gary B.]

Thanks Ken; Need help from '72 & '73 owners

Any '72 or '73 owners out there who can shed some light on door and ignition keys?

Gary

[Ken C.]

Re: C3 door locks & ignition switch & keys

my 72 has same key (C) for ignition and door locks

[Gary B.]

Thanks Ken; now we just need data for '73

Any '73 owners out there who can chime in?

[Robert R.]

Re: Thanks Ken; now we just need data for '73

Gary,
Yes the same for '73s. Square (E code)for Ignition and Doors, Round (H code) for Alarm, Spare and Center Glove Box.
Bob

[Gary B.]

Thanks all; So '74 and newer...

switched to the round (secondary) key for the doors. Anyone have any idea why GM made that change? To reduce wear of the ignition key?

Gary

[Jim S.]

Re: C3 door locks & ignition switch & keys

1974 - The ignition key was separated from the door lock keys on all passenger cars and conventional light duty trucks. Beginning with 1974 models, the ignition key operates only the ignition lock. This feature prevents ignition key information from being obtained from any other vehicle key or lock cylinder.

I believe that thieves had learned that by punching out the door lock cylinder they could use that lock cylinder code information to cut a new key and use it to unlock the steering column and start the car.

Jim

[Jack H.]

Re: C3 door locks & ignition switch & keys

I don't think the logic is one of anti-theft... Chrysler always made you 'exercise' your keys (use one to enter the car, the other to start and drive it). Being a MoPar brat, I once asked a Chrysler engineer what the reason was and he gave two:

(1) Help thwart owners from locking themselves out of the car with the ignition key left in the dash/steering column.

(2) Extent the useful life of the keys by creating an even wear cycle.

[Terry M.]

Re: C3 door locks & ignition switch & keys

My recollection of the stated reason, back in the day, was security -- just as Jim suggested.