According to the 2001 FSM fuse "F" in the PDC which is the one that protects the pink/red is a 20A. But if it says 15 in the owners manual or the PDC then stick with that. Either way, fuses can look good but be wonky and present problems. Don't really have a good idea on the 0.6V drop at fuse 5. There's a couple feet of wiring, the big connector on the firewall and a switch along the way but it shouldn't cause that much drop. Maybe there are some corroded contacts but if it works now I'd leave it alone.