I'm a new member here but, not to forums. Usually through a simple search you can find someone else who has experienced the same problem and I think it's awesome that we can learn from each other.

I've read a lot over the last few days and it helped me narrow it down. I'm working on a 2001 Jimmy 4.3. After correcting many other issues I'm left with a fuse that instantly blows. I'm hoping someone can tell me what circuit Ign C entails. It's a 20a in the box under the hood. When I put a new fuse in, right as it snaps, the front marker light blinks with the snap.

Any help or advice would be greatly appreciated !

 

IGN C circuit is responsible for A LOT of things, my friend.
It runs through your ignition switch, and then to your cluster, as well as back through the CRANK fuse before it branches out.

I suggest you find yourself a Haynes manual or something with electrical schematics.

marker lights should be a separate circuit though, so maybe you have some crossed wires somewhere.