Ignition switch on a Mercury Villager

SOURCE: Ford Falcon Futura AU II

the circle on the dash is smart lock..(ignition cut off like a kill switch immobilser) the only way to fix that is take it to ford or a macahnic its a module inside the ignition ,,,or the computers smartlock aint letting it go

SOURCE: H2 Hummer

Today 11-12-08 my 2003 H2 Hummer would not start. Checked battery it ischarged. Cables tight. Tried to start with portable booster pak. No go. Tridto jump start with my wife's Suburban. Still no go.
When I turn the switch I hear a single click and that is it. No engine turning over. While trying to start with key the headlights go out. Out of ideas, Will take to Chevy garage in am. Will post solution.

SOURCE: car wont start

I noticed you replace the crankshaft sensor, but not the CAMshaft sensor.
The Ignition module takes the input of both sensors to tell the coil when to energize.
This sensor should come up as an error code when you attach a obd reader.
Even if your light is not on - there may be a code. If it is not your vehicle originally, some people pull the bulb!

SOURCE: ignition switch fuse terminal is blowing red 40 amp fuse when i try to replace it

A fuse that is consistently blowing is telling you that there is a short in that system. Don't attempt to bridge it or use a larger amp fuse or you will have a major problem. You will need to start tracing wiring to destinations to find the short. If while moving harnesses around problem ceases to exist, look at nearby items where you are working and try to locate what was grounding. Sometimes people will stop if short disappears, leaving open the possibility of it happening again.
If you are not comfortable working with wiring, then leave it to professionals who do this every day. It's not really difficult but requires patience and a good bit of knowledge to do this right!

SOURCE: replacing ignition switch in 2001 chevy silverado

Not the igniton switch, its the ingition cylinder and or the housing. The switch is not part of what you are really turning. It's connected to it via gears. The common problem is the key gets worn out and the tumblers wear also. Eventualy they do not line up right and will not make the "bar" drop in the cylinder to allow it to turn from the off positon. If you have the title in your name and the key has never been rekeyed or the code has been changed you can go down to a dealership with all of the info for the truck and they can cut you a key from the vin number. You can try that first before you put a cylinder and housing in it.

Testimonial: "I really appreciate this info it makes sense and hopefully this solves the problem. it gets really annoying not being able to start the truci"