Hello,

The small clock has 3 wires going to it according to the Volvo Green book. The cable goes to a connector that plugs into the instrument panel behind the tach. The 3 pin plug has a green wire that goes to pin 58 a red wire that goes to pin 30 and a black wire that goes to pin 31. The green wire is the instrument panel voltage which allows the instrument lights to dim. The red wire is 12 volts for the clock to function (always on) and the black is ground. What I think you have is the clock light going to the 12 volts (light always on?)and no feed to the clock itself. Good luck.
Mario