No "High flash"

["Al Powell" <APOWELL@agcom.tamu.edu>]

Howdy, group.  Question de jour:  I discovered last night that my 
1990 200T no longer will execute the handy "high beam flick" when 
pulling the turn signal lever back against the stop.  I pull the 
lever back, and no flash - no high beam indicator flick on/off, no 
nothing.  This must have occurred recently.  Before I do battle with the 
Bentley, the following questions occur to me:

a)  Has this happened to anyone else?  If so, any war stories?
b)  Is there a (possibly defective) relay which causes this "flick" 
to occur? (Of course, I KNOW the solution won't be that simple.)
c)  Any way that my running 100W highs/60W low halogen bulba might 
have contributed to this??

Thanks for your thoughts.