I'm here 3+ years later to say the ignition switch and security ring connectors being the same size made me panic at home for hours from a no-start situation (immobilizer icon flashing) after replacing my evaporator. I spent a whole day working through troubleshooting steps only to stumble into your post. Not sure if you are still here @Tolman but I made an account just to say THANK YOU for pointing that [now obvious step] out.
P.S. my at home evap replacement took 2 days of daylight to complete on my own. Used a repair manual and took my time. Works fine and no 134A leaking into the cabin.
