I’m sorry if this isn’t posted in the right forum, it’s my first post after a couple years of just looking around the site. I recently got a 1988 Trans am 305 tpi and it ran a little bit rough but started each time and drove great, a couple nights ago I went to start it and it didn’t crank or make any noise. Initially I thought the starter failed but I touched the posts together briefly and it cranked just fine, I then took the trim off underneath the steering wheel thinking vats failed but the connector coming from the column wasn’t connected to anything and was just hanging there. I can’t find the other side of the connector going into the cars harness which makes me think it hasn’t been connected since I got the car so does anyone have any idea which route I should go to diagnose this? The fuel pump also doesn’t turn on when the key is turned which also makes me think vats

 

I think the fuel pump will still come on even if VATS is down. What you could be experiencing is a dead ignition switch, like it's never getting to the on/run position. One way you could confirm this, is by bypassing the starter enable relay down in the driver's kick panel with a thick jumper wire with two male spade connectors on it. If bypassing the relay allows the starter to turn with the key in start (briefly, the car still will not run so don't turn it over for long), you'll know the ignition switch is getting to the on/run position. If it doesn't, then the problem isn't VATS because VATS has been cut out of the loop. VATS also sends a square wave to the ECM to allow the injectors to fire, you can bypass that signal with this module. Or get a prom that has it tuned out.

 

To start off here, if it has run up until now with that connector unplugged, someone in the past has disabled VATS. Also, Komet is 100% correct, VATS will not kill the 2 second fuel pump prime upon key on, VATS only kills the starter and injector pulse. Now, since your fuel pump won't prime, AND your starter won't crank, your first check will be to establish whether the "fusible links" are OK, these are located at the starter and supply power to all of the car's circuits. If it was only the pump not running but everything else was working, a prime suspect would have been the fender mounted fuse, but that fuse won't kill the starter so it's likely ok. But, if the fusible links check out OK then give it a look just for the heck of it, it's a good thing to know the location of "just because" (it protects the ECM and fuel pump) . Since you've got the lower dash apart anyway, find the two fat red wires going into the ignition switch and check them for power, if they both have a good solid 12V on them, your fusible links should be OK. Do that check and report back your findings. Also, attempt to run all of the car's electrical devices and report back which do and do not work, right now we know you have no fuel pump or starter crank signal power, it'd make the diagnosis easier to know the functionality or lack thereof of all of the car's electrical systems.

As a last thought, never forget that standard troubleshooting procedures apply, but if the wiring has been altered in any way by any previous owners with more wirecutters than brains, things can become really hairy really quick. I have seen in the past where someone pulled the old "This circuit is dead and I can't find where it's lost power, so I'll just jump power to it from this other wire that does have power and make it run" hackjob. Sure the car ran, right up till the load of both circuits was too much and fried the second wire's power source, it took some serious "Automotive Forensics" to put that one right.......

 

Thanks for all the suggestions, I’ll check everything you guys mentioned as soon as I can when the rain lets up (have to love the pnw) and when my friends stupid Fiero stops having issues and tell you my findings.

 

So I’m looking around the underside of here and I wanted to find the starter enable relay behind the driver side kick panel but I can’t find any trace of it, I looked above the fuse box and behind the rubber and can only find what I thought was the door lock relay. Also does anyone know what the big black box with tons of wires coming out of it is?

 

Yes, the silver relay is your door lock relay. The black box I'm not sure of, my base model 89 Firebird doesn't have that, does your car have a digital dash? If so, it could be related to that.

 

Yea it’s got a digital dash, nothing else is in there. I’ve looked all over and up above the fuse box and above the hood release, there’s nothing but a ton of wires coming out of the harness. Is it possible someone cut the relay out and wired it directly?

 

Also the fuel pump is coming on for a couple seconds, I just couldn’t hear it the other day. I did replace the ignition switch since I had one laying around and it’s still doing the same thing

 

OK, so now we're gonna have to break out the voltmeter, or 12V automotive test light. I am enclosing two different wiring diagrams, one with VATS (1989) and one without (1988) . The thing is, only some 1988s got VATS, might have even been trans am only, but don't quote me on that, and all 1989s and later got it. Anyway, using these diagrams you will trace the starter circuit. As you see, the ignition switch is fed by two large red wires that I previously mentioned. You have to determine if both of those wires have 12V on them or not. If they don't it's likely the fusible link. if they do, have your assistant hold the key to the start position and check the fat yellow wire coming from the ignition switch. If no power, perhaps a failed switch or one that is out of adjustment and not being pushed far enough by the pushrod. If there is power on the yellow the next check will be at the dark green/ white (VATS) or the yellow (non vats) at the gear selector switch(automatic) or the clutch start switch(Manual shift) to see if power is making it there (with the key held to start, of course). If yes, next check is the purple wire at the gear switch (or clutch switch). Report back these findings and we'll go from there.

 

Hmm, the starter enable relay for my 89 camaro is right where your silver one is. Check the factory service manual for your year, they tell you where everything is located.

 

Been real busy over the past year while the car has sat, but finally got around to looking more into the issue. I suspect someone ended up swapping the whole steering column or just the ignition from a vats car as I haven’t seen any other indication of vats being factory in my car, I pulled more wiring out to check with the multimeter and I found a bad fusible link among the 3 at the starter wires and a bad section of the thick yellow ignition wire. Replaced them and now the car starts up and runs great, but it now backfires on startup so I’ll be looking more into this issue. I also went about replacing the starter with one I got from a friend as mine was acting weird but I nicked the transmission line so now I’ve got to replace those, can’t wait for a manual swap.

Thanks for the help everyone! First time being in any kind of forum