Key wont turn over

no info generic answer no by-pass have vehicle scanned for trouble code ----how did you evaluate that problem is security ---failing ignition switch -fuel filter/pump -- failing sensor loose or damaged wire and about 50 more reasons check and test first 3 to narrow down to electrical or fuel problem

Neutral safety switch, try turn the key on neutral, jiggle the shifter, shift thru it's range, it may have come unplugged, or an alarm cut off relay or such.

What year is it ? Turning the key on , nothing works ? Do the head lamps work ? are they bright ? Instrument cluster warning lamps come on with key on - check engine , air bag , ABS , etc....

Try turning the steering wheel while trying to turn key. It may take some force on the wheel, but don't turn the key hard!

Yes, because as the temp drops, so does the cranking amps of the battery.

The most common cause of a non-starting car is the battery. It is either weak, (low voltage) dead, (zero voltage) or has bad connections. (corroded or loose) I will assume you have a fully charged battery with good connections. (both to battery and starter relay) and I will assume that your starter don't work with the key in the start position.
If you remove the starter switch lead (small wire) from the starter relay and apply +12v from the battery to its respective prong or lead on the relay, and your starter cranks, your starter switch is faulty. (not to be confused with your key switch). If you jump the two large wires together on the relay and it cranks, then the relay is faulty. If you jump the two large wires together and nothing happens, then starter is faulty, or wires to starter are loose or broken. Picture of starter switch prong on the relay is pictured. NOTE: sparks are to be expected, so don't be too scared. Pictured is a starter relay that is seperate of the starter, on models with starter and relay mounted together, its very similar.

Check the main power fuse of 100watt

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try wiggling the steering wheel while you try to tuen the key. SOmetimes, the steering wheel lock is binding in the slot on the steering wheel.

the electrical portion of you ignition switch is going out.

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