Cadillac Repair: speedo cluster, digital voltmeter, blown fuse

Question
changed speedo cluster error keeps coming up on odemeter then cluster went blank ac heat led went blank car is a 2001 deville treid disconecting battery over night did not work thank you

Answer
Hi Eamon, This is one of those cases that a blown fuse, missing power or ground for the speedo head or a defective head could all cause the display to go blank or read error. Further testing with a digital voltmeter and shop manual will be needed to isolate the cause. Scanning for codes might lead you in the right direction but unfortunately a better quality scan tool will be required. Probably best to take it to the shop for diagnosis. Bill