Cadillac Repair: caddy display, cadillac deville, fuel heat

Question
Bill

 I have a 1991 cadillac deville.I just bought the car knowing the displays for fuel,heat control and fuel data ctr.are not working .
 I put a new body control mod.in and nothing
also rebooted by unhooking the battery for 20 min  and touching cables for 30 seccould you give me any clue what to look for?

            thanks for any help  Larry  

Answer
Hi Larry, This is one area that several componants share the same data line and if one was bad then it would affect the others. First make sure all the fuses are good. Then one at a time you need to unplug the fuel data panel, cliamate control panel, and then the programmer. Make sure the key is off when doing this and then turn on the key. If the display now works replace the componant that was unplugged. If no change then plug it back in and go to the next one. If unplugging all componants doesn't get the panels to light then the replacement BCM could be bad but more likely there is a power or ground problem or an open wire somewhere that needs to be tracked down by useing a manual and test equipment. A shop will probably need to get involved unless you have a manual and know how to trace the wireing with a voltmeter. Bill