1990 Firebird Pro Am Ignition Switch help

[sampitts74]

I have been having issues with my car occasionally deciding it didnt want to crank. I called the mechanic i bought it from and he said that it sounds like the ignition switch since it is the only thing he never replaced. I bought an ignition switch for it only to find out that the keys that come with it are meant to be used as a template and the real key has to be coded with a resistor chip on it. My question is, where can i get a key made that for it that wont cost me an arm and a leg since you have to find the right resistance for the key or whatever. And also is there a way to find the code without trial and error so i can have it ready for whoever i am getting to make my key?


Thanks a lot before hand

[Tech II]

First, let's get our terms correct here....what you are replacing is a lock cylinder, not an ignition switch(many people make this mistake).....

This is a VATS lock cylinder, that has a two wire harness connected to it.....The lock clinder comes with a "key template", to cut your new key....the key has to have the correct resistor code.....you measure the resistance of the old key, and match it to these values:


Key# Value (Ohms)
1 392
2 523
3 681
4 887
5 1130
6 1470
7 1870
8 2370
9 3010
10 3740
11 4750
12 6040
13 7500
14 9530
15 11800

But before you jump the gun, if the vehicle doesn't crank, look at the SECURITY LIGHT in the dash when you turn the key to "on"(don't crank)....it should come on for 5 seconds and then go out.....if it stays on after 5 seconds, the vehicle won't crank....the "usual" problem is one of the wires to the lock cylinder is broken or is broken inside the insulation and is making intermittant contact.......this can be checked with an ohm meter....

If the light goes out and it doesn't crank, you need to check the starter enable circuit.....

You have an alternative......don't replace the lock cylinder or key.....find an orange sheathed harness(with two white wires in it) coming down the steering column....follow it to a black connector....disconnect it.....buy a resistor equal to the resistance of your key......attach it to the half of the connector going away from the column......this bypasses the lock cylinder.....but now you are not protected by the PassKey system.......

[Blue Bowtie]

If you have an original key you can simply measure the resistance through the pellet in the key bow.

Short of that, follow Tech's advice to locate the VATS connector. Install a 10K potentiometer in the circuit (one end and the wiper contact) and adjust the pot to various resistances until you can extinguish the SECURITY light. You can skip the #1 resistance value since it hasn't been used since the mid-'80s. You'll have to wait about four minutes between attempts if you have the wrong resistance dialed up.

The resistance doesn't have to be dead-on. Here are the tolerances:



This is a more complete guide for your '90 F-Body:

http://www.wwdsltd.com/files/VATSSystem.html

[Blue Bowtie]

BTW - My local locksmith charges about $7 for a VATS/Passkey replacement, while the dealership charges about $30. Shop a bit and you might find the same thing.