Trim issue

I have a '99 Javelin Renegade with a 175 Evinrude. My engine has mysteriously been trimmed to the full up position. When I try to trim it down it sticks and goes back to the full up position. I talked to someone this morning and they thought that I had a bad switch. I unplugged the switch at the engine and the bow (individually) and the problem is still there. How do I get to the switch on the throttle and on the steering column? Or if anyone has any ideas or suggestions I would appreciate it.

Try swapping the 2 trim relays on the motor (under the cowl) and see if it will go down...mine got stuck in up position and would not come down either...replaced relay for $20 and its working fine now...