1994 Subaru Legacy intermittent problem starting

On some days (mostly winter) our car fails to turn over. There is no clicking or other noise. The stereo and heater will work, but when I turn the key nothing happens. The check engine light has been on for 3 mos (we were told that the timing chain needs replaced), but we haven't fixed it as the mechanic said the cylinders had irreparable grooves and the car would die within a year (1-1/2 years ago.) Anyway, the part of the ignition where the key is inserted was taken apart and checked without resolution of the problem. Battery is new and strong. I'm guessing it is an electrical problem because if you wait a couple of minutes, it usually will fire up just fine. It seems to occur more as temps climb near the freezing mark and then drop over night?