So my coolant light is ON, ac only working when driving, radiator fan won't kick in. I checked the 50 AMP fuse and its good. The fan works when hard wired to the battery. I am thinking that the fan relay, the black box with the fan wiring coming out of it might be the problem, part number A 025 545 59 32. I took it out but don't know how to test it if its working. Any ideas?