Fuse box diagram

Check battery and Battery cables make sure they are tight

If your 2000 Nissan Xterra has a brand new battery but there's no power to anything when you turn the key on, it's possible that there's an issue with the electrical system. Here are a few things you can check:

1. Check the battery connections: Make sure the battery cables are properly connected and tightened. Loose or corroded connections can prevent the battery from supplying power to the vehicle.
2. Check the fuses: Check the fuses in the fuse box to see if any are blown. If you find a blown fuse, replace it with a new one of the same amperage.
3. Check the starter: If the starter is not working properly, it can prevent the engine from turning over. Listen for a clicking noise when you turn the key, which could indicate a faulty starter.
4. Check the ignition switch: The ignition switch sends power to the starter and other electrical components. If the switch is faulty, it can prevent the vehicle from starting.
5. Check the alternator: If the alternator is not working properly, it can prevent the battery from charging and supplying power to the vehicle. You can test the alternator using a multimeter.

If you are not comfortable performing these checks yourself, it's best to take your vehicle to a qualified mechanic or Nissan dealership for diagnosis and repair.

What all does that fused supply B+ voltage too ? Do you know ? That would be your first thing to find out ! Do you know what a electrical distribution diagram is ? Do you know how to test electrical circuits with a DVOM - digital volt ohm meter ? Do you know what a short to ground is ?
Which fuse ? IGN A - 40 amp ,under hood fuse / relay box ? This fuse powers the Starter Relay and Ignition and Start Switch
Does your vehicle have a manual or automatic transmission ? The starter relay could be shorted inside , It's also located in the under hood fuse box . If you pull the relay out of the box it's plugged into an look on the bottom of it you would see four sets of numbers ! 30 & 87 an 85 & 86 . If you were to jump 30 to 87 in the relay box the starter should spin the engine over , not start an run just spin ! 85 & 86 is the control side . Could be the ignition switch !
That 40amp fuse powers a lot of subsystems !

Here is a web site for free diagrams !
http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model an engine , Under system click on electrical distribution , under sub system click on power distribution . Then click the search button .Click blue links one at a time . First blue link scroll down to the second diagram . You will see Ign A 40 amp fuse at the top of the page .you will also see it powers the igintion switch ,look at last part of ignition switch , when in start or run that 40 amp fuse powers all those other fuse's plus three relays i see there also . A/C compressor relay , rear window defroster relay ,daytime running lights . Any one of those circuits could have your short . You need to isolate the circuits , pull fuse's till the fuse doesn't blow !

What powers that side of the fuse box ? Do you know ? Do you know what a power distribution diagram is ? You need to look at a diagram to see where those fuse's get there power ! Could be only powered when the ignition switch is on ! Suggest you view wiring diagrams . Do you know how to do electrical testing ? With a volt meter . Electric Testing Techniques You Need to Know

The Trainer 32 How To Read An Automotive Block Wiring Diagram

View wiring diagrams here http://www.bbbind.com/free_tsb.html

Enter vehicle info year , make , model and engine size . Under system click on electrical distribution , under subsystem click on power distribution . Click the search button , then click on the blue link. Look at the second diagram down . You'll see a IGN SW - BATT 2 30 amp fuse powers the ignition switch .In the on position the ignition switch powers the under hood fuse box . are you testing with the key on ? You also have a right instrument panel an a left instrument panel fuse box , do you know about these ? What is your main problem ? No start ?

Check power an grounds for ignition switch , voltage drop test the starter circuit . Go to youtube an check out videos on basic electrical trouble shooting , voltage drop testing ,how to read a wiring diagram .Then go here http://www.bbbind.com/free_tsb.html free wiring diagram ! Look at power distribution under electrical distribution . Check main fuse's Maxi fuse's that power the ignition switch ,IGN.C fuse 20amp in underhood fuse box ,then check crank fuse 10amp in same fuse box .Check the starter relay in the under hood fuse box . Check the circuit form ignition switch to the starter relay , pull the relay out an look on the bottom you should see 4 set's of numbers 30 - 87 - 85 - 86 . Pin 30 or 87 should have battery voltage ,one or the other ,not both . if you jump those two at the base (where it plugs in ) not the relay pins . It should crank the engine ( if starter is good an there are no opens in the circuit ) Pin's 85 an 86 are the control side of the relay ! You may want to check out videos on how a relay works also > Good luck hope this helps

You have to know year make and model. Then Google it.

If the truck cranks over you have voltage at the ignition switch ! From starter to switch , First off starter to what switch ,ignition ? There is a 175amp fuse that supply's battery voltage to the power distribution center - fuse box under the hood . On the lower right side of the radiator support, below the battery !

Check if the small wire on the starter has power with the key held in crank position. If battery voltage there, either bad battery cables or connections, or the starter solenoid has a malfunction. If no power when key held in start, it could be the safety switch (a clutch interlock switch on manual transmissions, or a park/neutral switch on automatics). You may need a wiring diagram to see the start circuit from ignition switch to the starter solenoid-some have a start relay in that circuit.
Find wiring diagrams at http://www.bbbind.com/technical.html
Free TSB's and wiring diagrams for every make and model.

( one question i have is every time the ignition fuse blows do i need to replace the starter relay? ) NO ! You have a dead short to ground on one of the circuits that fuse feeds. Do you know how to find a short circuit ? Video's on youtube show how. The fuse that blows ,is it IGN - A 40 amp. located in the under hood fuse/ relay center ? That fuse feeds B+ voltage to the ignition switch ,which powers up other thing's ,fuse's etc.. Not just the starter relay ! I see five other fuse's that get power from that fuse when ignition switch is in the start or run position . In the I/P fuse panel the gauges fuse #4 10amp , air bag fuse #10 10amp , turn b/u fuse #16 20amp. , Plus trans fuse #20 10 amp ! Pull out these fuse an try to start the van. if the ignition fuse doesn't blow the problem is in one of these other fuse circuits. There is one more fuse that get's B+ power from the ignition switch and ign A fuse ,crank fuse fuse #8 10amp. this powers the control side of the starter relay .
You can find a free wiring diagram here http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model and engine . Under system click engine , under subsystem click starting. Click the search button then the blue link.
If you pull those fuse's i mention and it still blows the fuse look for a shorted ignition switch or wiring from ignition to the starter relay , not the relay itself. Park neutral safety switch . Isolate the circuit , pull the relay out of it's socket ,pull the crank fuse #8 in the I/P fuse box. with a ohm meter check to see if that part of the circuit is shorted to ground. Do you know how to do that ? Do you have a volt ohm meter ? You can buy one cheap at parts store .

resistor.............tell the mehanic