Mercury 50hp tilt & trim Problem

[Ripplingh2o]

I've got a 1996 Mercury 4-stroke 50hp. Beginning last fishing season the tilt/trim began to work very intermittently. It always works while pounding over waves out on the lake, but whenever I'd launch or land the boat (or back at home in the garage) the tilt/trim sometimes worked then sometimes didn't. Seems for the most part it's only when tilting the motor up. Down seems to work just fine. I believe it's an electrical problem. I find it extremely difficult to believe my dealer when he says the MOTOR is bad. And a new motor is three hundred bucks. Anyway, I've cleaned all the electrical connections to ensure of no corrosion. I believe the tilt/trim button on the throttle routes through the tilt/trim button on the engine cowling because when the button on the engine cowling fails me the throttle tilt/trim button doesn't work either. Seems if I hold the cowling tilt/trim button in and giggle it alittle the motor finally kicks in and up she goes just perfectly. Any recommendations or suggestions to help me figure out this problem? I'm thinking of ordering just a new cowling switch and see if that fixes the problem. My other concern is if the wiring is faulty inside the motor itself because I've tried to check all the wiring up from the tilt/trim motor to the tilt/trim switch. Really believe there's a poor electrical contact somewhere but to find it is a real hairpuller. Thanks for whatever help you could provide.