About a year ago I installed red lights in the dash of my 92 z. All was good for about 4 months then i lost one bulb. Then 1 month later i lost all but the speedo bulb. I have taken them out numerous times and replaced them but the speedo one is the only one that still works. What could be the problem? All connections are good. Please help, i hate turning on the dome light just to look at my guages!