i have the same problem on a 96 ghia model. several segments disappear when the weather is hot, eg the sun is out. I have been informed that the display consists of two pieces of glass sandwiched together with liquid in the segment and electrical contacts at various positions. The sun heats the glass which expands. This in in turn cuses the liquid not to make proper contact with the eletrical contacts. If you gently run your finger over the glass. NOT TO HARD you will notice the display appear, but will fade away. You could try covering up the display, put a cloth or foil sun blind over dash, although if its not working properly now it never will. it might work once the weather cools down. A new module for my mondeo is in excess of