Thank you, this seemed the most helpful, but my fuse keeps blowing out, any suggestions

Tell us which one of those fuses keeps blowing

In reference to your diagram, it would be number 12,
Thank you for your time

Here's how the Starting circuit on your Xterra works and how it looks
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So if you look at the top of the diagram you can see your Fuse 12 that keeps blowing
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Follow the circuit and it goes through the Park/Neutral switch to the PNP Relay (I showed you that in the diagram of my original reply)
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This is referred to as the "Control Side" of the Starter circuit
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In your case something is blowing that Fuse 12 and appears the two most likely reasons in that P/N (PNP) Relay or the Park/Neutral Switch (or its wiring/connection)
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Maybe pull out that relay. Place a new fuse in Fuse 12. Turn the Key to Start and see if the fuse still blows
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Now of course the starter won't turn because there's no PNP relay inserted, but it will put power to that Park/Neutral Switch and if the fuse still blows then you know it isn't the PNP relay causing it. You'll examine the wiring and connection to the Park/Neutral switch and if it looks good, then test the Park/Neutral switch to see if it's shorting out
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But if the fuse doesn't blow, then maybe suspect that the P/N (PNP) Relay is causing the problem and then try replacing it
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Those would be good starting points to try to nail this down

Awesome, yesterday it was a crazy day so all I did was change out the relay and placed a new fuse. Truck started and drove a little before the fuse blew out. Does this mean I need to change the neutral safety switch?
Thank you in advance

well it's 20 years old so it could also be a wiring short in that leg of the circuit too
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That Fuse 12 gets power in both ON and Start
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Maybe turn the ignition to ON and grab the wiring harness at that P/N switch connector and move it a little like it would when the engine is running and see if it shorts out and blows the fuse
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So don't dismiss a possible wiring/connector issue. If you replace the switch examine the connector for corrosion and the wiring for any fraying of damage
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Also, it wouldn't hurt to inspect the terminals of the socket where that relay plugs in
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Look for evidence of corrosion or melting plastic around those terminal sockets

Hello there!
Would you happen to have a video or instructions on how to replace the neutral safety switch, or how to get access to it.

There's youtubes on how to replace the neutral safety switch.

I'll post one of a guy showing how to do it with the transmission out because it's easy to see.

The thing is, some guys say you have to drop the transmission pan to change the switch. Other guys say it can be done without doing that.

One thing I can say, the guy showing how to do it on the transmission out of the vehicle isn't dealing with "clearance issues" with the exhaust system.

But either way it's a pain in the ass and I understand that most people want to just replace a part and hope the problem is fixed.

If you haven't read my replies carefully I keep telling you to check the wiring to the neutral safety switch.

I even told you to move that wiring harness around KEY ON to see if the Fuse 12 blows.

The reason I'm harping on this is because of the way the wiring to that switch is routed.

It's comes up from the neutral safety switch on the transmission, up into the engine compartment, right next to the catalytic converter's heat shield and the exhaust manifold and it's just begging to cause a problem. (electrical short).

So in your case I'd inspect that loom starting in the engine compartment. Look if there's any areas where it's "rubbed through" or melted through..

If you can't see anything from there, unplug the underhood connections on that wiring loom.

I think there's 4 of them. (2 are for that neutral safety switch)

Then get under the truck and pull that harness (at the neutral safety switch) down a little, (maybe 8 inches) so you can inspect the area's of the loom that are close to the exhaust and cat shield.

Look for damage.

You may find an area of the loom where a wire or two that has its insulation melted off of it. If this is the case you can just wrap some electrical tape around the individual wires and then tape up the loom.

Maybe even grab a heavy duty zip tie and find a (cool) spot to attach that loom to keep it from contacting the hot exhaust system again.

That would be a lot easier than replacing the neutral safety switch.

So if you have to replace the neutral safety switch it comes with a new wiring harness. But replacing the switch is a lot of unnecessary work if all you have is a wire shorting to ground and blowing Fuse 12.

So here's some helpful pics and that video.

Two of the 4 connector locations for that wiring loom:

Wiring loom:

Youtube of changing the Neutral Safety Switch:

https://www.youtube.com/watch?v=AA4S4mCrJ78

Hello there!
Thank you for your time and your patience more than anything.
I had a guy help me yesterday and the wiring was somewhat corroded, he pat he'd it and it worked.
No fuse blown, I left came back at night, started it worked fine.
This morning I tried starting it but no crank again.
I checked the fuse and no blown.
I ran my little system and got a P1605 code again.
Sorry to ask bit what would be my next step?