Just bought a 2000 Silverado LS extended cab with 8' box. All turn signals and flashers work ok when turned on but there is a constant clicking from turn signal flasher when ignition key is on and without signals turned on. PO said new flasher is needed. I installed the flasher he provided but it buzzes so I removed it quickly. I can put my finger on flasher and I can tell the click is coming from it. Is it the multi-function switch or something else. One fog lamp does not work and another source said he fixed some lights and this same symptom went away. Please help