urbanmisfit

I have an 87 22r, recently the overdrive relay started clicking frantically. The problem comes and goes. While driving the overdrive seems to repond accordingly to the problem. It will only kick in some of the time, sometimes it will stay on for awile and sometimes it will just fire on and off in short bursts. Turning the windsheild wipers on will speed the clicking noise up. I have read in some other post that it is tied in from the wiper fuse. If i keep the OD button off the relay doesn't click at all, everything seems normal except the obvious fact that i have no overdrive. What might be the problem? Thanx in advance