all gauges went south

["Robert W. Murphy" <rmurphy@os.dhhs.gov>]

This morning after filling up my 90 Spider I noticed that my gas gauge did 
not read correctly.  Instead of reading full, it read about 3/4 full.  Once 
on the highway I then noticed that the tachometer was reading only 1400 rpm 
and would not move above that.  The speedometer was reading 60 mph and as I 
accelerated it stayed there.  It later jumped to 80 and then 90 but I had no 
idea how fast I was going.  Then I noticed that the water temp gauge stopped 
at just below 100 degrees.  So now the tach, speedo, gas gauge and temp gauge 
are not working properly.  I checked the oil pressure and voltage gauges and 
they seemed to be working properly.  When I shut the car off after arriving 
at work, I turned the key on to see if all warning lights were working.  They 
all lit up including the water temp warning light.  What gives?  Bad ground 
somewhere?  The car was not driven all weekend.  The tach and water temp 
gauge really worry me.  So I would like to solve this as soon as possible.  
Any ideas?

Rob Murphy
90 Spider
Coral Springs, Florida