I checked the voltage at the 80-amp fuse, and it was 12V (on both sides). I took the plug apart where the glow plugs come into the relay box and tested at the metal pins for voltage (when someone turned the ignition on). There is no voltage at all, but there is still 12V coming to the relay through the fuse. Someone said you should hear it click on, and then after a period of time, click. I hear neither. Does this mean it's the pre-glow timer relay? It seems to me it is, but the part is not cheap to be replacing if it's good. If you have any other suggestions let me know. Thanks.