OK, if I understand your issue, you turn the key to start, sometimes the key comes back to the run position and sometimes it doesn't correct? You say you bought a new switch. Which part? The key cylinder (pic A) or the actual ignition switch (pic B)?
If you bought part A, that part needs to be programmed into the system. Otherwise the security system will prevent the engine from starting because you have the wrong key (different from what is programmed into the system)
If you bought part B it won't change the issue either. It only moves with the ignition interlock cam to the position you want. The real issue is inside the mechanical section of the shift interlock in the column. There is a spring that moves the interlock and also lets the key rotate forward/back. It has either corroded or partially broke.
It is possible to replace it BUT it is actually much easier, faster and usually cheaper to replace the steering column itself with a used one. Then you would take your current key cylinder out (part A) and replace the one in the replacement column with it so you don't need to reprogram the security system to a different key.
Images (Click to enlarge)
Friday, March 31st, 2017 AT 12:36 AM