87 944 Dash guages and roof stop working

I''m kinda new to this forum, but not to 944''s.  I had an 86 944 and loved it and thought I knew the few glitches the car has but I''ve just purchased an 87 944 and driving to work the gauges all dropped as if the vehicle was off.  When I got to work and went to lower the roof that wouldn''t work either.  When I left work everything was working again but soon after stopped working.  I''ve traced all the wires and can''t find any loose connections (such as a loose ground) or anything.  According to the manual the gauges and roof work off of the same fuse but a fuse doesn''t blow, then un blow itself.  It seems like something maybe tripping up the entire system after it has been on for a while because when I turn the vehicle off and then back on everything works again.  Has anyone experienced this before?  Any suggestions?
 
Thanks,
-Patrick

Hi,
 
Just a suggestion, i had a problem with my 86 brake lights, the fuse was good but they wouldnt work, i took it out, looked put it back in and they worked, looking on the fuse, it was a little oxidized, i put a little wd on the prongs and slid it in and out of the slot a few times and so far so good.  Maybe your fuse has the same problem,  needs a little cleaning up.
 
Eddie