Alright, I have posted another thread on this problem, but I have since discovered some more info. about the wiring and have narrowed down my search for my current no start issue.

Basically, I have an '88 Trans-Am with the 305 TPI, auto. trans. I have no power being sent to the starter solenoid when I turn the key...basically, I get nothing when I turn the key. The battery is good, it doe not have the VATS, and the rest of the harness has been put back together as far as I can tell since I pulled the dash out for firewall repairs. I took power from the battery and directly touched it to the back side of the larger 10 gauge purple wire on the fuse panel labeled "crank" and the car cranked over and started. So it is somewhere in the starting circuit between there I guess. There is a smaller like 16 gauge wire that is purple with a white stripe going to the other side of the "crank" fuse that I imagine supplies the power to the larger wire when engaged/activated from wherever it is activated from between the key and that fuse. That is where my issue lies and where I need a troubleshooting diagram or wiring diagram of some detail to help me diagnose this. In short, where does the power come from between the key to the fuse panel which then supplies to the starter itself? That is where I am at on this now.

 

All I really need is a decent wiring diagram or troubleshooting tree so I can figure it out myself...

 

I think that the smaller purple/white wire is for the cold start injector.

I'd check all your fuseable links and any In-Line fuses to be sure there is no problem there. Sorry - I don't have a 88 diagram for Ya' !

 

Alright, finally figured it out. I knew it was a plug somewhere not plugged in...my dumb *** missed the plug to the neutral safety switch. I had a feeling it was a problem somewhere in that safety switch circuit...that's what it was.

 

Quick question for u? How did u rule out that the ignition switch was not out?

 

I tested the wires coming from it in the on position and while in the crank position and had signal when cranking off the ignition switch...so I knew it had to be down line somewhere.

 

And which wire was that sorry its cause ive had this problem for awhile

 

I too have this same problem on my 91rs auto 305. have not been able to start it for the last month, every 100 tries itll turn over, start, and die right away. Any ideas? was it the nuetral safety that went out then or bad wiring? THanks

 

Hey, sorry, no longer subscribed to this thread. The wire I tested at the column was the yellow wire out...meets down the column into one of the 3 big harnesses down there...you'll see them when you pull off the plastic trim piece. You should have power to one of the larger gauge wires all the time...I think it's red on mine, and the yellow one will light up/show voltage when you turn the key. I have a trans-am, so I have wiring for both manual and auto. trans cars. So I had a wire for the clutch switch near the fuse box as well as the harness for the neutral safety switch at the gear selector. It turned out I just somehow missed the plug for the neutral safety switch...plugged it in, fired right up.

If you are getting the car to crank over, it is not likely one of these wiring issues. If the neutral safety switch/wiring or ignition switch are the issue, the car wouldn't crank over normally at all. Unless it is loose or has a bad connection of some kind in the ignition cylinder and wiggle causes it it to shut off because it thinks you turned the key off or something, I would think the issue is elsewhere if the car cranks over but doesn't start.

 

well on mine it just wont turn over at all...so i apply voltage to the yellow thick wire coming down from the ignition ur saying and see if it will crank over?

 

Yea. Sounds like that what he is saying. Sounds like ignition switch and neutral switch is always the colprit if you haven't touched the wires and it just suddenly done this by not starting. My ignition switch actually fried after so many times to get it start it would start then days it wouldn't. Then SMOKE one day it started. Thats how i knew my ignition switch was bad.

 

NO...the yellow wire is where I am checking for voltage. I don't know what will happen if you apply voltage to it...probably nothing. Yellow is where I have the test light or multimeter on to see what voltage and when. There is a purple wire about the same gauge that runs right nest to the yellow wire on the clutch safety switch and the neutral safety switch by the gear selector. It also runs up into my fuse panel box under the dash behind the fuse labeled "crank". It's the only solid 10 gauge purple wire in my fuse panel. Put power to it and it will probably crank. If it doesn't...you have a similar issue...probably neutral safety switch or starter.

 

I still am having same issue and been following the tread as you guys post trying to figure this all out. (91 305 rs auto) My yellow wire is getting voltage, maybe not enough?? whats it supposed to read? How would i apply voltage to the purple wire? I dont think its the nuetral safety cus when the wires were all grabbed and wiggled while trying to turn over, got like half a crank. So stumped from here.
I was throwing a code before this all happened but now that the compter was unplugged and plugged back in its not registering, is that normal? Thanks for the help!