Picked up an 91 z28 5.7L yesterday previous owner wired a push start button with the key on position.what would i have to do use the turn key start, i hate the push button.thanks

 

Follow the wiring to see how button was installed ( more than one way to do it )
then return the wiring to original setup with a wire from the Ign switch to starter through the safety switch ( relay optional )
Typical GM starter circuit shown below ;Check where changes have been made in your car

 

He may have only cut one wire to install the button. If so then just look for where the wire was cut and reconnect it to the harness that goes to your ignition switch.

 

Sweet ill check it out later today and let u guys know how its wired.i bought the car from a towing company was sitting for a year .thank you for the help

 

I looked at the push button wiring ill get some pics, from wat i saw two wires one was from button ran to purple wire on the wiring harness under the hood, second wire ran from push button to the BATT fuse box under drivers side.i also notice a brown wire cut from looks to be a brake light switch just above brake pedle wich is connected to a yellow wire going to the starter

 

Ok i disconnected the push button setup . And still doesnt start using the key

 

Obviously.
You took out the dodgy wiring but you did nothing to restore the original wiring as per the diagram above did you

 

You need to find the starter wire ( yellow ?) from the Ign switch and reconnect it to the purple wire
(through clutch switch or NSS so can't be started in gear )

Check your wiring
Yellow wire can't go to the starter , you already have the purple going there
( otherwise the PB would not have worked )

 

Yep, the purple will need to connect to the output wire from the ignition switch.

there is the possibility that the pushbutton was wired in as an ignition switch bypass due to a problem preventing the ignition switch from working properly.
It could be that they just didn't feel like replacing the ignition switch.

 

Alright guys ill check it out thanks again ill keep u guys posted

 

Alright ive checked the wiring nothing was cut, im thinking it could be they bypass some thing, car wont crank or start nothing happens?. Doesnt make sense to me now that the pb is gone the car wont crank or start when before the pb was connected it would crank n start with the key on the on postition

 

It makes sense if:
1. The purple wire going to the starter is no longer hooked to the 12v out source from the ignition switch.
or
2. The wire is hooked back up correctly and the ignition switch is faulty.

 

So you have checked that the wiring is complete from ign switch to starter like in the diagram above ?

On position or start position; Two different things

 

Yah wiring is fine. And the key would be on the on position then i push inn the pb to start .i got a new ignition switch with new key i hope thats wat it is

 

You mean barrel?
Ign switch with the wiring is at base of steering column ; not where the key goes
At present you are just throwing $$$ around because you are yet to confirm
if you have 12V (or not ) on the starter wire out of the Ign switch
when the key in the START position

 

Do u have pics of what the ignition switch looks like
Thanks

 

Tried

https://www.thirdgen.org/forums/post...471-post7.html
https://www.thirdgen.org/forums/tech...-trans-am.html
https://www.thirdgen.org/forums/tech...h-problem.html
https://www.thirdgen.org/forums/post...55-post24.html
https://www.thirdgen.org/forums/post...75-post11.html

 

check the wires at your neutral safety switch

 

Little point at present because he has not re-installed the factory starter wiring
All he has done is remove the PB wiring ( that was working)

 

Ok ive checked the wiring and nothing is cut.tomorrow ill check if im getting 12v from the red wire on the ignition switch then to the relay .i think they just bypass something i need to figure out

 

So how was the PB wiring you removed connected to the purple wire that goes to the starter??????

 

Some how they manage to put one side of the pb wire through the purple wire and wraped around the purple wire without cutting it

 

OK
So you need to get a DVM put one end on the starter solenoid and one on the yellow wire
out of the ign switch and see if you have a complete circuit ( trans in park).
If not work back to points along the circuit until you find a connection

 

We got 12v at starter purple wire,but no power to the starter

 

Makes no sense,
where on the purple wire do you have 12V; ign end or starter end?
Purple should run to starter ;obviously did does because engine started when purple wire got 12V from the PB
So if you have 12V where the PB connected you should have 12V at starter

 

+1

Also, since the person spliced into the purple wire without severing it, it seems highly likely that this was a fix for a bad switch.

 

[QUOTE=305sbc;5217712]+1

Also, since the person spliced into the purple wire without severing it, it seems highly likely that this was a fix for a bad switch.[/QUOTE

Yes ill check out the switch today, thats wat i was thinking they bypass the switch

 

hey guys im getting no power at the starter??, car got new starter and ignition switch for the starter, idk what else to do im lost, the only thing i could think of is VAT on the ignition switch .

 

POST # 13
Start at yellow wire out of new Ign switch ; have you got power there?
If so ;have you got power into starter relay?
Jumper the 2 heavy wires ( bypass ) at the relay and see if have you got power into and out of the safety switch?

 

VATS is on the key barrel; not the Ign switch at foot of steering column

If it started with the push button; it is not VATS because VATS takes out the starter and fuel
If it was VATS related ; you would have power at the starter relay but not out of it

 

i checked the fuses and im getting nothing on my test light for the crank fuse 3 with ignition on and on the crank position . plz bare with me all this is new to me.how do i check if im getting power to the starter relay .thanks

 

Omg dude everyone here is trying to explain on the steering column there at the ignition switch there is a yellow wire that runs to the neutral switch on the clutch pedal or over by the shifter if it is auto follow that yellow wire from either the the ignition switch or the neutral switch see if u got 12v coming outta both if u do ur problem lies somewhere in the purple wire that goes from the neutral switch to the starter another way u can do is use a paper clip on the neutral switch disconnect it the connector an put the paper clip in between the yellow wire an the purple an try to crank it by the key if it starts by the key then u got a bad neutral switch

 

 

should i be getting 12v from the purple wire from the starter??.btw i do have 12v from the ignition switch n neutral switch . i am getting 12v to the starter .but still not cranking

 

you should get 12 volts to the purple wire only when the key it turned to the start position, have a helper turn the key all the way and test for 12v on the purple wire at the starter, at the spot where the push button was tied in and at the neutral safety switch, If not, make sure your ignition is OFF, run a wire from a 12v source and probe the purple wire at your safety switch and see if the engine cranks, if so the wiring is good from the safety switch to the starter, this gives you a starting point, let us know how it turns out, we'll help you out...

 

hey i took the ignition switch/tumbler out to replace it and found a broken wire , would this cause and these issues

 

yuuup

 

The tumbler where the key goes is not the IGNITION SWITCH
On the purple wire?
you are making no sense because when you had 12V on the purple at starter
before from the PB the starter worked

 

Honestly I am just going to straight up tell you its your immobilizer. Same deal with my car, I got the car so cheap cause it was off an estate and they couldnt get the car running or anything. Turns out those old immobilizers are messed up,which I then wired a push button start, it doesnt go through anything just straight from the starter to the button, key must be on and push the button, so take out the button wont solve the issue if your immobilzer is still messed up. Just like me, if i didnt want the button id have the same problem of not starting with a key. So take a look at that.

 

Wheres the immobilizer located and is this something that is easly changed

 

Depends who did it, normally under the dash there should be a little black box but im not entirely sure, I never did care for immobilizers so when I installed my pushbutton its still in there.

 

It sounds like you are referring to an aftermarket alarm. The OP's trouble is most likely with the factory Passkey system or starting circuit.

 

hey ase doc im looking for the key decoder module i got a new module i need pics i cannot find it.thanks

 

I would advise the OP to spend some time familiarizing yourself with your car. Vetteoz posted a wiring diagram above of the starting circuit that looks like it's from the Helms Factory Electrical Manual. There is no better diagram to be had. As far as component locations go, the electrical portion of the ignition switch is on the top of the steering column about 10" from the firewall. The starter enable relay is under the driver's side kick panel. The theft deterrent module is behind the RH side of the instrument panel, attached to the HVAC housing. Focusing on the components and wiring shown in the posted diagram, use a 12V test light to test for power at each point in the diagram as you turn the key to start.

You may well find that the start enable relay is not closing. This would be a VATS Passkey issue and we will jump off that bridge when we come to it. First, verify power/no power through the circuit and post your results. Resist the urge to replace parts until we verify what you have.

The broken wire at the key cylinder is likely from the one of the contacts that read the ignition key resistor pellet. That will cause your passkey system not to allow engine starting. There is a test sequence that will prove out any failure in the VATS system. We will go there once we know that the VATS system is what's causing your no start.

 

I still believe you are barking up the wrong tree.
Think about it;
you say it started with the PB which supplied power direct from battery to starter.
Why would it not then also start from the Ign switch which supplies power direct from the battery if you reconnected the starter circuit wires correctly?
As previously noted;
assumes the Ign switch is working which may be the reason switch was bypassed and the PB installed in the first place

 

Ok so I have been following this thread for a bit, and one question I have is this.

If OP says he changed the ignition lock cylinder with a new off the shelf one, and is using that key to try to start it, would VATS be preventing it from starting? I know that this may not have been the original problem, but unless I'm misunderstanding something here, did he not just pile a new problem on top of an old one?

 

What Im wondering is if the VATS start enable relay isn't working and was bypassed with the PB switch. This would be easy to verify with a test light before and after the relay. If the car starts and runs that must mean the VATS was allowing injector pulse.

EDIT: Now the OP has replaced the key cylinder and says that he found a broken wire. If he did in fact disable the VATS key contacts, the VATS will no longer allow fuel or the start enable relay. It may also be that the VATS was bypassed by the PO and the start enable relay was never properly bypassed, thus the PB switch. All of this can be verified, starting with testing for power throughout the start circuit.

 

Nope not alarm, I dont have an alarm and the car never did. I just seen a blackbox under the dash and wasnt sure the purpose but either way, my issue was an old immobilizer, so I bypassed it straight to the starter. The key still needs to be on and the fob still needs to be there for it to actually fire. I turn the key on with a fob nearby and push the button itll just turn over and over, put the fob there and itll fire first turn over.

 

this is most likely the reason ,i agree

 

prob an ign switch problem in the first place. If it started before with the pushbutton then vats is prob not an issue.