I know this has been covered in detail so i will make it short. 05 cavalier I unplugged the passlock connecter at the cylinder, when i measure the resistance of the yellow wire to the ground I get 18K ohms key off or on. I find that this cant be right. i have a haynes manuel and it is such a simple looking switch with a resistor but i am stumped as to why it doesnt measure a open in off and 18K on.

Do it right and use a PJLX module.

yeah, buy a BYPASS module and do it right.

For those of you who dont want to pay money for a box that is a 3$ relay and .20$ resistor. The problem that i was experiencing try to bypass the passlock was that if you disconnect the 3 wire plug right below the ignition switch and measure the resistance from the plug it will not work. If you leave it together cut the yellow wire and measure the key side of the yellow wire and ground the other meter lead you will get your magic resistance. It works great and will save you twenty bucks if you need more explanation email I will be happy to assist you rather than tell you to buy some part or rig a switch that throws the security light on.

Well when you install a "part or rig" correctly you won't get a security light. Yeah, don't go out and buy the part that was designed to do the job, solder in a resistor that will make your factory security useless. That way it can be stolen. That is what I would do.

is it the 555L? if so i have one i dont need anymore, works perfect.