i have a 1980 SA and when i put it in reverse the gauges light up and thats the only time that they do. theyre off in every other gear
this is really weird lol
can anyone help?

 

yes it is a wiring issue. when the gauges light up, do any other lights like park lights and tail lights also light up? do the backup lights even come on? this might be a tough one to diagnose since the 2 wires that connect to the backup switch on the tranny in no way connect to the park light/headlight system. hopefully others will chime in with some ideas.

 

that's easy, just don't put your car in reverse lol.

seriously though, its probably a pinched wire in the tail light harness that is connecting the reverse circuit to the tail light circuit causing all the lights to get power. it will probably actually be really easy to find and fix.