Blown starter fuse

head lamps work, jumper cable jump starts fail>?y/n?
ah a simple failure, not dead engine complex.
this has only 6 causes, of no crank. using voltmeter makes the job near childs play. if you do that, guessing will be $$$$$$$
A/T trans or M/T auto or stick , not the same.
you shorted out wires under the dash with that key act.
that blows fuse if lucky or blows up very very expensive electronics. nobody here knows what you blew out.
only using meter finds this. a voltmeter (DMM)
all one word left off, I broke off the metal key inside the ignition switch so then hot wired the switch
bingo now I under stand what you did.
a new ignition switch is best.
I think there is no IMMO here
I found a free service manual (real) online
let me see what fuse you blew up.
if you short out the key switch or starter relay
yes the fuse link blows. for sure.
fuse 19 is the starter fuse, not blown.
volt meter check IGN switch has power white wire is power in,if dead, link is blown
turn to ST start, and ST pin goes to 12vdc
as does starter out relay pin B/Y to starter

now the free manual
https://procarmanuals.com/pdf-online-nissan-300zx-1993-service-manual/


now you have full schematics in the EL chapter,.
see 1 below in part.



start path fuse battery must be good.

Turn key to On.
Turn on headlights manually... Do they come on?
Are there any lights on the dash?
If yes to these, battery is possibly not the sole problem.
Check for good, tight and clean connections at battery terminal posts!
If yes to above, continue on & get a helper... Turn key past on, to Start position.
Do you hear a click sound at time key is turned to Start?
If yes, then ignition switch is not problem, starter relay is getting power, and is now sending power to starter, but starter is not working.
Pic any No's... Then look there.
Good luck.

( 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 .

Have you checked the alternator or the starter?

The problem could be a shorted park netual safety switch . Do you know what a wiring diagram is ? It shows all the componets involved in a electrical circuit ! You IGN.1 fuse 40amp , GM calls it IGN A fuse 40 amp . It feeds the ignition switch and pin 30 at the starter enable relay .When you turn the key to the start position it sends B+ voltage to #8 crank fuse , located in the I/P fuse box ,from there it goes to the park netual safety switch , to pin 86 or 85 of the starter enable relay ! If you pull the relay out of the fuse box an look on the bottom you will see this four set's of numbers ,30,87 & 85 ,86 You can test at the fuse box where the relay plugs in . Here is a video on how to test . The guy presenting the video uses a horn circuit , but it works the same way . It happens a lot , the park netual safety switch shorting out . It may or may not be the problem . VEHICLE RELAYS Operation Diagnosis
Here is a web site for free wiring diagrams
http://www.bbbind.com/free_tsb.html Enter your vehicle info . then under system click on engine , then under subsystem click on starting . Then click on the search button an a link will pop up , click on it .You will see all the componets , connections , wiring colors etc... for the starter circuit for your vehicle .

Hi.

Check ignition switch fuse. This is a 20 Amps. see that it has not blown. In 2004 Fuse should be nr 8 in the power box under the hood (newer models #24).

Once you are sure that battery, fuse and wires are OK, check starter and ignition switch. Check if there is 12V to starter while cranking. If there is power and the starter motor does not turn, then the motor is gone.
If there is no power to starter motor when you crank, then the ignition switch located inside the steering column may need replacement. Before repairing, try reading error codes with a code scanner.

The 40 amp maxi fuse in the underhood junction block (According to the information I have, there is only one 40 amp fuse in there..) goes directly to the ignition switch. From there, it goes to the buss bar in the Instrument Panel Fuse Block where it feeds several smaller fuses. It also feeds the starter relay in the Underhood Fuse and Relay Center.

My biggest concern would be: What caused the fuse to blow in the first place?

If you get nothing else from my preaching, get this:

Fuses don't blow for no reason....ESPECIALLY not a 40-amp Maxi Fuse!

I can't count how many times I have heard people say: "It's JUST a blown fuse." WHAT???

I have been at this for 35 years and I can tell you that blown fuses are reason for major concern in my book. That 40-Amp Maxi Fuse just saved your truck from burning to the ground and you need to find out why!

The only way that fuse is going to blow is if there is a direct short to ground between the Underhood Fuse and Relay Center and the Instrument Panel Fuse Block (The only "component" between these two is the ignition switch.) or if the secondary side of the starter relay circuit is shorted to ground. The secondary side of the starter relay feeds the "S" terminal of the starter solenoid. (at the starter)

I think the first place I would look for the problem would be the circuit between the starter relay and the starter. It is likely to be shorted against the exhaust or engine block. If this is the case, it most likely fried the starter relay in the process. (which is why the fuse no longer blows and the engine no longer starts)

Aftermarket remote starting units are also usually tied into this circuit. If your vehicle has one of these, it could very likely be the original source of your problem.

At any rate, there should be no rest, truck running or not, until the reason for the blown fuse is found. You will most likely get the truck running in the process of locating the reason for the blown fuse.

Could do. I think the ABS relay is housed in the same box as the starter relay. If so, you could have a blown fuse box link. Find the starter relay and see if it clicks when someone else turns the key to start. If not, see if there are volts on to the relay (there should be voltage on one side of the contacts when the ignition is on), there should also be volts on the coil when the ignition is turned to start. If not, check whether there is power to the fuse box (fuse links might have blown). If no power to coil, check gearbox park interlock switch - there is not much that stops a starter motor from turning, even in a sophisticated car like a Jaguar.

Make sure battery has a full charge and battery connections all good. Any fuses in the diagram, test for voltage, some are hot all the time, some go hot with the key on.
Use a digital multimeter across battery posts, everything off, the generic spec for a full charge is around 12.6 volts. Leave the leads hooked up to battery, have a helper turn key to crank, how far does it drop? In my opinion it shouldn't drop much under 10 volts, I wouldn't argue with 9.6 volts.

try to start it in neutral if does then you have a bad neutral swich