fto gearbox problem

really need help with my fto, its doing weird things, i put it in drive, it does not move at all, i put it in reverse, it goes fine, there is is clicking/ticking noise from underneath the dash, mechanic says its the relay, sometime the neutral light flashes as well, can someone please tell me / advice me something.

No Drive? Mmm, I'd take a guess at the Torque converter as worst case scenio...

http://auto.howstuffworks.com/torque-converter4.htm

Check linkages on the Gearbox.