My M37 has the covered instrument lights, the M37 you have should have red lenses, one on each side of the speedo. Like Bill W said, The panel in your truck could have changed. In my picture lookingl at the panel, top left gauge is the volt, top right is the fuel, bottom left is the water temp, bottom right is the oil pressure, the two blank things one on each side of the speedo are the panel lights, they direct the light back into the panel.