OK, Once and for all... Does ANYBODY have instructions for completely disabling the factory security module?. I tried in another thread to get a definitive answer. I did every search I could think of and the best I came up with was............................................... .. "TWO SCREWS, TWO HARNESSES AND YOU'RE DONE" .................................. Unfortunately, that is a tad bit less than descriptive enough. I found the box near the ECU, it does in fact have two screws holding it in, but only one harness plugging into it. So, does anybody know where this famous second harness may be found? Anybody ever actually done the job that can explain it in a little better terms? I'm getting really burned out on pushing this 3800LB MF'er from spot to spot so I can fruitlessly fumble with trying to figure out why it won't start. No spark. No signal to the Coil relay, ECU has no problem codes. I have plenty of fuel and the pump and CSV are activating. Pretty sure the PTU and CAS are good. Ignition switch is in sad shape but no one has given me a yes or no as to weather the switch could have anything to do with a good crank and no spark scenario... I am trying to eliminate possibilities one by one. The factory security system needs to go bye bye pronto. Please!!!! Anyone that can lend some advice here? .................................................. Rod.

 

did u try putting a multimeter down in the harness going to the TPU and seeing if its sending a signal to the coils? (Course, Im not sure what exact voltage to look for, have to take a look at my fsm), If its good there i'd jam a multimeter into the harness goin to the fuel pump next... best I could come up with

As for the security module, ive never tried to, I use mine... but I was under the impression pulling the brain out all together disabled it completely

 

Fuel pump is definitely working... no doubt about that. As for the PTU, it's not getting a signal because the relay for the ignition coils is not getting power... It's killing me!!!! And to think that once I get it started I get to Replace the water pump, timing belt kit, buy four new tires, replace the suspension, have the body work and paint done, fix the interior and blah blah blah

 

With the help of the online FSM wiring diag and your info provided, this is what you should check out with a voltmeter:

(Colors referred to are just what I colored the diagram, not the ACTUAL wire color on your car.)

This is the beginning circuit on our cars, the diagram is primarily of just the starter, and ignition circuits, but if you aren’t getting power to your ignition relay, here is what I suggest you check:

1.) The blue line is the 12v out of the ign. switch that energizes the relays for about everything from the ign to the fuel pump. That line should turn on and off w/ the key. Check to see if it does.

2.) BOTH of the Red lines, should have 12v on it ALL THE TIME. Check them both.

Check these out and get back to me.


EDIT: I know you asked about the security system, but if you can check these points out, you will know if it is your ignition relay, ignition switch, an open circuit, or your security system which is preventing your car from starting, it is the easiest way to tell what the most probable failing circuit is.

EDIT EDIT: Make sure to check them off of the Ignition Relay, not off of the other ends, you want to check to see if the power is actually reaching the relay before backtracking down the system. BTW, sorry if this seems like such basic and obvious steps, but sometimes, they are the easiest to miss.

 

Thanks RP, That is certainly usefull info. What i am looking for though aside from that , is a definitive answer specifically in regard to he security system itself. I want the factory system disabled. It must go. All the posts from people who've said they have done it gave no real information or instruction as to "How to do it" Where in Gods name is the second harness that is mentioed? Anyone? Bueler?... Bueler? Did the original factory key from a 1990 model have any kind of "chip" in it? I don't think so, but a friend of mine siad his '90 Maxima did... All I have are two worn out aftermarket keys with a little black stick-thingy that must "Touch" the ignition switch while turning the key or it won't start... Is that for the factory alarm??? or is that something that was added? All I know is that if you don't touch the cylinder with it, the car won't even crank. Anybody have any insight here? Again, you have to forgive what seem like stupid questions because this is my first Z32 and I have found nothing from searching thta answers these seemingly basic questions. Can any of you just go have a key made at home depot that will start your car???? If so, then I know that the stick thinymabobber is not related to the factory system. The aftermarket system has two wires going into the harness to the factory security module by the ECU, but I don't know which one is telling the other one what to do. I'm planning on removing both, but I need a full understanding of exactly what the factory system does and does not do first. Will the factory system (if triggered) allow the car to crank but disable it's ability to spark? or will it just not even let the car crank? I don't know... Hopefully somone here does know though. Anyone want to try an experiment for me? Roll down the drivers window, close and lock the doors then reach in and unlock it from inside then try and start it... What happens (Besides the bloody horn honking and hazard lights flashing)? Will it crank or not? Also, the keys I have for the car will only unlock the doors (barely) but will not lock them. I had a new key made, but it has the same problem. I just need someone to answer some basic questions is all... Rod.

 

^^^^^^^^^^ Sooooooooo...... Nothin' ? Anyone? Somebody has to know something for cryin' out loud. Pleeeeeeeeeeeeeeze! For the love of Z's somebody throw a dog a bone already. Lord knows I've bailed plenty of people out of horrific situations in the 280ZX section, now it's my turn to get a little help.... anyone?

 

Rod here's the online manual, maybe it'll help.
http://300zx-twinturbo.com/cgi-bin/manual.cgi
Also the 90 key did not have a chip in in. My old original and the 2 cheap key copies wouldn't master a fresh cut and I had a "spec" key made for $15. The spec key takes the worn out key back to original. I was having all new keys made and had to do it to keep from ruining the new blanks.
Had a mechanic friend remove my factory alarm, I think he had to do a jumper when he did. I have no idea what he did. I do have an aftermarket on it.
I'm not sure if I remember correctly, but isn't there a second module somewhere under the hood in the engine bay, seems it's under another type module like the PTU or something. I maybe thinking of something alltogether different.
The online manual should show the locations.

 

I have the online manual and unfortunatley in this case it's about as usefull as screen doors on a submarine. It doesn't have any info about the security system that is really usefull to me. Actually, you just helped me a great deal by confirming that the factory key was in fact... Just a key. That means that my little stick-thingy is for the aftermarket system. Progress made!

 

I may have said it before, but I'd put the wiring back to spec, get rid of the aftermarket alarm and start again.
Mine was done at a place called Latino Auto Repair here in NW Arkansas. He has a subscription based access to print outs and such it was helpful as hell. Can't remember the site.

 

Ok, I finally remembered to bring my FSM in from the car... after looking through it I found an extensive troubleshooting section for the factory alarm, one of the sections says if starter motor does not operate with ignition switch in ST position, check... Battery, Theft Warning Relay, Starter Motor, Starter Kill Circuit, is your starter motor turning? or is the problem after the starter motor?... still looking at wiring diagram to figure out exactly how system works...


Edit: by the way... how does the little security light on the steering wheel blink when you are trying to start the car with all the doors closed, and how does it blink with doors open, etc... there are quite a few t/s procedures that depend on how the light is blinking

 

This is actually a fairly impressive security system.. it seems to have sensors tied into everything even the headlights, and it has a sensor that can tell if your door lock tumblers were tampered with... but it seems the real unit to remove to get rid of the system is the theft warning relay... from what I can tell it puts a ground on certain signals when the security system is engaged... I dont know how much rewiring was done for your aftermarket system though, to completely remove the entire security system would involve alot of wires, the relay, the control unit and 14 sensors.


Edit: The theft warning relay is in the engine bay fuse/relay box, the one on the top row with just two, on the left... if your looking at it from the drivers side fender

 

I'd have to go back and reread the thread, but I think he said it was turning over and no fire/spark.

 

Oops... im blind , its not the factory alarm system then, because it has nothing to do with the starter path after the starter motor, it only grounds the signal between the starter relay and the starter motor

I think RPS13 is right about checking there... then I would check continuity between the starter motor and the ignition coil relay, of course need to make sure the ignition coil relay is working, its what completes the circuit through the coils

 

Awesome! You two guys have been a big help. Thank you so much. Now, I'm going out to tackle this beast once again. I'll keep you posted. Thanks again. By the way... My PDF version of the FSM didn't have anything on the security system... Not sure why? Oh well, you guys helped me narrow it down and give some direction. Awesome. ........................................Rod.

 

Rod another place to check for information is carfiche. It's self explainatory once you get in it. Sometimes like right now the carfiche for the 90 says TnA which is not currently available, check back at the top of the hour and a new manual will be available. May have to check back several times.
http://www.carfiche.com/

 

Carfiche is where I downloaded the PDF file for the FSM. I guess they left out the security system portion of the manual though. Everything else is there from what I can tell though... Thanks for all the input. I'll be out there most of the day messin' with the car now that I have some good info. .................................................. ..................Rod.

 

Yeah, the online FSM doesnt have the theft system in it... but if you need more info, I have the two 6 page fold outs of the wiring diagram, and circuit diagram.

 

i wouldn't recommend the '90 manual from carfiche, go with the newer 94 or 96 fsm from that site. the 90 looks like it was scanned on a first generation scanner.