2006 75 hp elpto serial no. 1b244674 power tilt trim problem

[barefootpoppy]

I was having a problem with the power trim at full throttle to get up on plane. The motor drops right back down. I did replace the tilt trim assembly with a new one. The symptoms are exactly the same as the old assembly. When out on the water at throttle up to get up on plane the motor just drops right down. I can go about 5 miles per hour and the motor stays up on increase speeds the motor drops right down. There is a trim sender on this motor its a 2006 75 elpto optimax serial no. 1b244674. Could the sender be bad? Are there relays or something electrical to check? Hard to believe a brand new oem mercury trim assembly would be faulty and produce the exact same symptom as my old trim assembly. Help?