Just put in a Concert2 CD player for my A6,put all the plugs in the
back,but no light display when i turn the lights on.Which colour wire
supplies the light display,and where should it go in the new head unit.It
all worked ok with my old Concert tape player.Help if possible please.

My 2001 A4 Avant 1,8 TS (8D chassis, corresponding to B5 saloon, motor
variant AJL) used to have coolant temp at a consistent 90C (is that
192F) during suburban driving, ambient temp between 0C-10C (32F-50F)
About one month ago it started showing coolant temp at a lower temp of