Ign A 40Amp fuse pops on start up

I have a '98 Tahoe v-8 350 4x4 2-door tahoe, once I turn the key to start, it pops the 40amp fuse marked Ign A (located under the hood)...any ideas?

Probably have an open circuit wire somewhere and when a charge goes down that wire it arcs to something else causing it to ground out and pop your fuse. I was trace your ignition wires under your dash to the main fuse box and see if any are exposed.

Just my 2 cents..if its not that , I hope you get it solved..Electrical issues can be a real biotch sometimes.

yeah they can. it was driving good all day, went inside, came out, and POP!
my tahoe is still at work for the night, I hate that.
can it be a wire on the starter? I replaced the starter a couple of months ago.

Possible I suppose. As a vehicle gets older it's wires casings become more brittle. Especially the thicker ones ie : starter + & -. This can create micro cracks when moving them to change things and that can lead to arcing issues. Also if you got a cheap-o starter the built in solenoid can be failing/faulty.

The IGN A fuse powers 3 contacts in the ign switch, one of which is the "crank" contact. This fuse also supplies direct voltage to the starter thru the "starter relay" when energized.

Try pulling the starter relay (underhood fuse box) out and go to the crank position. If the fuse holds I would suggest replacing the relay 1st. If that doesn't help then it could be the wire (purple) from the relay to starter or the starter itself.

Let us know what happens.

yeah they can. it was driving good all day, went inside, came out, and POP!
my tahoe is still at work for the night, I hate that.
can it be a wire on the starter? I replaced the starter a couple of months ago.

check that the wires are secure at starter and did not get damaged on any metal..

because it is intermittent it is most likely a damaged wire..