Q&A

 Journeyman

I would be looking at the body control module

First, FIRE your mechanics.
Then go to a new one and ask him , or her ;-) to replace your ignition switch and make sure that the wiring connector is fully inserted into the new switch.

I have had similar problems same car and still have electriacal issues. I can give you some start points that may help. Figure out which fuse or fuses are operating problem devices. Check them and connections inside for corrosion looseness etc. The fuse block interior connectors tend to widen and provide dubious contact. Replace any vaguely suspect fuses. Wiggle them to see if they flicker. That includes the female end in the fusebox. If this produces a flickering contact, pull fuse box and inspect the female end for corrosion etc. but first try electronic component cleaner, a small file if that is suspect, which may save you from pulling the dash apart to access. Disconnect the negative batt terminal before ripping into fuse box as wiring to airbags could short and explode the mechanism, causing personal injury. Work from the simple fixes to the more comlex ones as it is a nightmare of wiring harnesses. Check battery terminals, ECU terminals and look for corrosion and wire that has been scraped or broken. I am not a auto tech, but have been trying to solve my electrical system problems that were far more involved than yours. I am down to fuses that break when the brakes are applied. I have had this to 3 mechanics and study and sheer persistence has paid off, but its not for the impatient. Beware, as this is expensive done by pro's and find one that knows his stuff or you will regret it. do not allow them off the hook and partially fix things, leaving the rest to you. Don't allow free openended privilege as they charge by the hour until they find the problem. A lousy electrician could spend his formative years and finance his childs college education on your dime. Demand frequent updates and ask questions and get a good manual with schematics and educate yourself. Or you will be educating his child later. They will not commit to an estimate, as they are unable to until the cows come home and suppers on the table. They can also be prima donnas as they got you by the short ones without their expertise. Find another. And if they say its your muffler bearings, run like hell. let me know, I charge nothing but my own experience involves all the above and still my brake lights are out. I thought about installing battery powered crossing guard stop flags with lighting but dismissed it for aesethic reasons. :>) Best of luck, it may be the easy fixes I have outlined. But please remember the battery disconnect, it caused a short for me that fried the harness, and hours of rejoining burnt wiring. Its not rocket science, but close.