ok, heres the deal I bought an 89 5.0tbi firebird almost 2 years ago, been sitting, just going to fix it up then start driving it, originally I had all kinds of issues, that were fixed when I replaced the ecm, the vats has been bypassed and is working correctly, but when i turn the key to start the car nothing happens, I do have the car hooked upto a push start button wich works fine, that is tied into the purple wire under the hood. car runs fine too, just no start with the key. I have replaced mostly everything in the system, since its old and I intend to fix up the car and drive it everyday soon anyways, I replaced the ign switch, still no start, and I tryed adjusting it about every possibly way to engage but it wouldnt start, so I picked up a new nuetral safety switch too, still no start, I tryed bypassing the starter enable relay to see if it was bad today, still nothing with the key. So heres what I cant firgure out, is if there is anything else left in that circuit that can be replaced as far as relays go, all the wiring looks perfectly fine too, no cuts or pinches that I can see. I know for a fact that the big purple wirle attaches to the starter works fine, because I have my button attached at the harness running along the intake, but I dont know how to tell were there might be a problem at, I was going to use a test light at the other switches to see if the problem is inline with it, before it, of after it in the circuit, but since I am one guy with no one else to help turn the key, while I check I cant think of many other options. Any ideas on this would be great, like I said I do have a push button tied in, so I can start the car, but would like it done correct. Also as I stated I know it is not a vats issue. Thanx for any help

--Brian

 

So you have 12V from the batt going through that switch to purple starter wire?


No need to turn key on.
You need to get a DVM , put it on Ohms and test for continuity along the circuit from the terminal on starter switch all the way through to the solenoid terminal.
That will tell you where break in circuit is
Typical GM circuit

 

Mine has an issue where the NSS connector won't stay connected well enough to start the car - a zip tie fixxed my issue.

It's not the volts that counts on the purple wire, it's the amps - I had 12v+ on mine always, but it would rarely start since there wasn't enough of a connection at that NSS to draw the amperage needed to run the starter.

None of that may help, but I put it out here for you - take a peek at how well that NSS connector actually connects (same for ign switch).

 

thanx for the diagram, and help guys, I'll look into more on m day off.