in the past several months my 91 240 wagon has exhibited a seemingly random no start condition, usually after being run for some time. i turn the key and all the lights on the dash illuminate and i can hear relays clicking. i have replaced the starter and solenoid, neutral safety switch and the ignition switch. sometimes if i turn the key to the start position and hold it there, after some time it will start. i have tried to notice things that might be related and there seems to be a correlation with the air conditioning. most of the time the a/c works -- at least the fan always blows -- sometime it blows cold air, sometimes cool, but not cold air. the no start SEEMS to be associated with times when the a/c only blows slightly cool. additionally, sometimes when the a/c is running fine, and switch off the blue a/c switch, the fan continues to blow cold air as if the switch were still on. it is hard to tell if these things are related or not. any ideas?