Hello, shorts to grounds can be very difficult to find most of time, but just so we're clear, the fuse pops if you have either the Starter relay in or just the Fuel pump relay in.
Since this only happens when going to crank the engine over, you will need someone to help when trying to locate the short.
The best way to find a short is to put a test light in place of the fuse, that way when you find the short to ground or bump the wire that is shorted the test light should go out.
But having the Fuel Pump disconnected will be necessary because the test light will find a ground through the fuel pump. It will probably be the same for the Starter Solenoid; it will light the test light as well.
You'll notice that Fuse 8 also feeds the (Fused Ignition Start) for the Transmission Control Module. Since the fuse doesn't pop with both relays pulled, the short to ground shouldn't be down the TCM wiring, let's hope.
But try to find this C121 connector first because it will be the easiest to start with. Check the connector for any corrosion as well. I've added the pinouts for both C121 and C321
The circuit design on this will make it more difficult though, do you hear the Fuel pump prime for 2 seconds with a fuse in place and fuel pump relay in?
https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester
Here is a video on using a test light to find shorts to ground:
https://www.youtube.com/watch?v=Lfk-vmeK4G0
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Thursday, May 30th, 2024 AT 6:46 PM