Back when the DeLorean was first designed, it was planned to have the HVAC decal to be all black so the car was wired to fully illuminate the HVAC when the headlight were off and run the illumination through a resistor when the headlights were on to dim it some. What happened was some owners in warmer climates found the heat from the full illumination was melting the plastic face plate. Then the cars also came out with decals with white lettering on the decal which eliminated the need to light it in the daytime.

So 10 years ago it was common knowledge to remove the “Light Relay” and install a jumper in its socket from pin 87a to pin 30. Or you could cut off either pin 86 or 85 from the relay and then the relay would work like the jumper and you would only get full illumination with the headlights on and no illumination when headlights are off.

With LEDs installed in the HVAC the dimming did not work anyway. What I did was just do the hardwire fix of connecting light green/white (light relay) wire to the red/brown wire on the red resistor socket. With either change, the red resistor is not used and that resistor could be removed. I used the red socket for my electronic otterstat and my light relay is blank if I need another relay socket.