I'm having the same problem, has anyone successfully fixed the issue?
02 Ram 1500, 4.7 automatic, almost 167k miles
Check engine light is on. Fan was not working and fuse 39 was blown. Replaced the fuse, swapped the relay, and cleared the CEL. Now the fan works, but the CEL stays on with the same p1491 code. I've read about other issues with the wiring inside the fuse box corroding. Think this could be related? Open to suggestions.