Ford Repair: mercury, 1999 mercury cougar, automotive electrician

Question
I have a 1999 Mercury cougar, I couldn't get a Mercury guy on here so I am hoping you can help me. I have been having allot of problems with it. I already went through 2 alternators and a starter and took it to a mercury dealer who fixed that problem. But another problem had been driving me crazy now. When I go to start my car and a turn the key all the way it doesn't do anything, no click or any noise at all. If I leave it on acc you can watch the check engine light and the security light above the temp control blink in unison with eachother as well as a humming noise which sounds like its coming from the fuel pump which also hums in order with the lights, now its really bad if im parked on a slight incline, i can get it to start if i push it onto level ground and time it just right and it will wanna crank for a while then it will turn over. it also does it on level ground just not as bad. and every now and then it will stall out while driving and ill have to wait to start it again. I took it to a shop and they thought it was the security alarm, then they replaced the ignition switch and now there telling me its the wiring harness. but that doesn't sound right since it will start as long as I take it off of the incline/ decline onto level surface. any ideas? Its a 2.5 v6  

Answer
There may be a problem with you're wiring harness.The key to you're question is in the fact that the symptoms change as the grade changes.This points to the security system which has a built in feature to cut off the alarm when the car is at a tilt as a result of being towed.Perhaps it is defective.This is a new one to me.Take the car to an automotive electrician that specializes in problems in automotive electronics and wiring.