matthew combs

I have a 2003 trailblazer lt with 3rd row seating. Got the l6 in it. I'm having an issue with limp mode. It just happens randomly. Now when the truck goes into limp mode the key will not turn back all the way so you have to hit the little release under the steering column. I've replaced the ignition switch several times, thinking that was the issue. I recently replaced the entire wiring harness to the ignition because after some research I found that so many systems are run through it that harness it sometimes doesnt have enough power to fully power the transmission. However, today I pulled the number 48 fuse inside the truck for the ignition. Wasnt blown so replaced it and like magic. Truck out of limp mode. Any ideas on what's going on?