this is my first post on here. i rebuild transmissions for a living so having scanners and tools is not a problem. this is my wifes car and she loves it so i have to get it fixed. sometimes when you get in the car to start when you turn the key the service engine soon light will come on and you have to wait for it to go off to try it again. sometimes the 2nd try will work and sometimes not. I have checked the codes and no codes are available. i have replaced the ignition switch 2 times and had several keys made. i thought of tring a pcm but i cannot find a used one to buy to try. it might do it today all day long and then not do it for a month or two. it seems to do it worse when its raining, damp outside or if its humid outside it will do it. i have no idea really where to start checking or what to do. Please if any of you have any ideas or have had this to happen please help me with this. my wifes is getting angrier every day. she also has a 03 trailblazer that the ac will quit when you are driving down the road and not come back on until it sits for a while. i have replaced the eletric fan clutch and put a new orfice tube in it. i have 2 headaches that i can not figure out. thanks in advance for any help.
