HELP! instrument light failure

["Sherry & Chuck Clark" <clark@rmi.net>]

 Ok guys,

          I'm too lazy to try to find Ned Ritchies tech tip about the 
instrument light failure for an 87 5000 T.Q.  Sometimes they work 
perfectly but most of the time(getting progressively worse) they do 
not even exist. I know  I'm not the only one out here that has had 
their instrument lights fail and I'm figuring that it's not too tough 
to fix them-with the parts of course. The headlights and all outside 
lights do still operate properly all the time-just instrument lights 
are toast.
           TIA!
                                Chad Clark
                                         '87 5TQ -only 15PSI boost.