I’ve had this problem now for a few years and have replaced the dimmer switch, don’t have leds, and wonder why the dimmer is not dimming. All the dash lights stay on but will not dim.
I’ve checked the fuses and they all visually look good, at least the fuses I think I should be checking.

The previous owner had a defi red racer boost gauge on the steering wheel but I don’t recall if it was tapped to the dimmer.

Any suggestions would be great

 

anyone?