Hello TGO! I figured a forum should be the place I turn for help for this problem. I just bought a 92' Firebird and I'm having trouble with it's no start condition. I've already sucessfully (I think) bypassed VATS via the resistor method causing the light to shut off. I didn't have the keys to the car and had to replace the ignition lock cylinder and plan to get the correct vats key in the future. However I have a new battery in it and it won't crank. All electronic functionalities seem working besides the engine starting. I replaced the Positive battery terminal that goes to the starter but that didn't make any difference. I've heard that relay bypasses are a thing but I don't know which one is my starter relay and or how to bypass it to see if the engine will actually fire or not. It's been sitting for about 4 years. Last registered in 2014. Engine isn't seized and the starter looks replaced. any help is appreciated. Thanks much!
-Kal

 

Start here or with a factory service manual

https://www.thirdgen.org/forums/elec...pass-vats.html

 

Those schematics are very helpful thanks! I'm really still not sure which is my starter relay in my car. Is it under the carpeting in the 92'? I've seen 2 other relays which I temporarily unplugged to test them for power when the key is in the start position. None of the pins showed any voltage in this position though leaving me to think I haven't yet found the starter relay??? Edit: one relay I found was right next to the fuse box, the other I found was up near the steering shaft mounted in a little housing type deal. Hope that helps

I'm also entertaining the thought that it could be neutral safety switch problem or the whole Passkey Decoder Module is somehow corrupt or malfunctioning. And like I said before the security light acts normal with the Method A resistor bypass method. It comes on for a few seconds and then shuts off after it's satisfied. Removing the resistors results in the security light staying on.

 

The starter relay placement is shown in post number 2, the relay has been removed and there is a piece of wire in the socket.

 

On my 88' GTA the starter enable relay was located higher up near the fuse panel and you had to remove the hush panel to access it. The relay itself was actually mounted on the body of the car in mine, you will know you found it because of the thicker wires on the ends of the socket that consist of one green and one yellow on each end as shown in the links Scooter posted . Then make a jumper wire with thicker gauge wire and insulated spades on each end and you can verify if the relay is working by inserting the jumper on each end of the socket.

 

I found the correct relay. However doing the relay bypass doesn't work (jumping relay-pin 87 to 30 closing the circuit that the relay would close). There isn't any power coming from Starter Enable Relay Control when the key is put in the start position, as the schematic suggests it should in order to close the circuit and actuate the relay. Do I have a bad Passkey Decoder Module? Is there any way to check to see if the engine will crank bypassing the module like applying 12v to that pin?

Also why does my battery terminal hook up directly to the starter solenoid? I'm so confused. Thanks for the help thus far 'scooter'

 

If you jumped 87 to 30 you have eliminated the relay, and associated VATS, from the issue for cranking.

Your problem is either wiring, the NSS on the clutch pedal or the ignition switch (if you have power in the rest of the car)

There should be 2 terminals on the starter, one for the battery wire, and the feeds to the C100 for the power to the car and the starter solenoid with the wire from the C100 to your ignition switch

 

I found something that is definitely not right. I opened up the center console and tested the neutral safety switch. Continuity tests while moving the shifter resulted positively. The NSS itself works fine but when I traced it's cable, I found that the wire harness is disconnected. It's dangling near the starter enable relay without any signs of another empty harness that corresponds to it. So the question is... Where does the NSS harness plug into?

 

You have an auto or manual trans? I think the TBI cars have the connector for the NSS at the clutch pedal and the auto selector, so if one is plugged in the other is irrelevant

 

Yeah I have an auto. so basically the "unplugged" harness is actually where the clutch pedal safety switch would be if I had a manual? Shoot that's no good. Now I'm back to square one again. I think I'll check both terminals on the starter to make sure they're getting good contact and test the pins at the NSS to see if they're working correctly.

Edit: the only think I could potentially make out as a problem is that there's only 0.5v on the starter relay at pin 30 when measuring from chassis ground.

 

Sounds like I need to take it to a mechanic to get it fixed? I've checked everything and can't find any of the typical problems like vats or NSS or faulty ignition switch. My dash turns on when in run position and same with start. The temp gauge flutters when starting but I don't get any crank-age at all and no relay click either. whatever the source of power is to the starter enable relay. It's not providing a full 12v like it should. What controls the starter relay and does it need replaced? Also the starter is tested and good.

Edit: Looks like I've stumped the community and I've got a firebird that can't be saved. (please help anybody)

 

I had a crazy idea. Would it be possible to splice a different wire that is 'start mode' switched that woiuld feed power to the relay? I could put in like a pushbutton start. My fuel pump turns on just fine when the key is in run position so in theory the car should start if I were to bypass the existing starter circuit and make my own.

 

You can do that, but if you can't troubleshoot your existing problem you might want to take it somewhere to get it fixed properly, or get a service manual and go through the troubleshooting procedures as I suggested in my first reply.

We can't see what you have in front of you so it is hard to know what the problem is. These cars and starter circuits are very simple. You need to get in there with a test light and/or miltimeter and start looking at the circuits to see what the problem is.
It could be a bad ignition switch. It could be a broken wire/It could be an open connection. It could be a poorly seated terminal or connector set. It could be a bad battery. It could be a bad ground. It could be the NSS on the auto selector. It could be a bad starter. It could be a resistive wire in the circuit. It could still be VATS since you only think you bypassed it properly.

Get a service manual
https://www.ebay.com/sch/i.html?_fro...anual&_sacat=0

It's this one, cheapest one I saw quickly but with shipping
https://www.ebay.com/itm/1992-Pontia...ia!07083!US!-1

 

So I figured out a bypass solution. The ignition switch was completely ok but something beyond one of the wiring harnesses isn't quite right and won't provide the 12v needed to actuate the starter. So I spliced into a 12v switched source and put a push button between the starter relay and the new 12v line so that when the button is pushed it provides 12v directly to the yellow lead of the starter relay. After doing a relay bypass to jump the green and yellow wires, the circuit was completed and the engine was able to start with the ignition in the run position and using the pushbutton as a "start position". Now I just have to piece back together my steering column correctly so I can finish my racing steering wheel mod.

 

Funny enough, I just encountered this same issue. Car was running and starting perfectly fine (LS swapped car) I have the correct VATS key so no bypass module and after my final session at the track 2 weeks ago - No crank. Fuel pump etc turns on, and the gauges act like it's cranking, but nothing. Inspected fuse box and nothing is blown. VATS module / solenoid is activating on key start but the signal is not strong enough at the starter solenoid to activate the starter (I measured only 6 volts at the end of the trigger wire)

There is another 30 AMP relay that is AFTER the VATS with some pretty big wires that has been messed with at some point, it's getting decently hot on crank - I think this may be the culprit. I will let you know what I find as I am determined to get this straightened out. It has to be something simple.

 

Your car has the crappy flat relay for the starter. You should replace it with a better/newer relay or just bypass it altogether

 

Do you mean the VATS / Starter Relay? I jumped it today and no dice. Then after ripping the entire interior apart and double checking my NSS connections, etc. I went to try and crank it and it worked. Mildly frustrating that I didn't find any gleaming errors or loose wires and that it slowly came back.

 

Even though I can hear it activating the VATS starter relay (clicking) any chance it could be a weak signal from the ignition switch?

 

If you have a manual transmission the NSS could be carboned up inside from use over the years. They are not a very good design and should not be carrying all that current for the starter solenoid.
It could also be a bad starter/ignition switch on the column, same deal, carboned up.

I would start by checking the voltage when in crank on the inside of the car before the C100 connector. If the voltage is low then there is a good chance the resistance is inside the car.

The problem may have just been fixed by plugging/unplugging connections and moving wires. Could have been a slight amount of corrosion in one of the connectors

 

I have a power probe and each time i turn the key The relay shows up as ground and not power. Power goes into the relay but what comes out is ground, What could be the problem?(P.S: New starter relay, new ignition switch and a new battery has been installed)

 

The way you are testing it.

 

Make sure when testing with a multimeter that your black probe is grounded on some unpainted metal (I personally test for continuity between a known ground and the metal ground first before anything else). and the red probe goes on the location you want check voltage for. Make sure your multimeter is on 20 or 10v DC. If you're putting the black probe on anything other than a "chassis ground" you'll have effects from having a relative ground. When I checked my starter relay measuring from big yellow wire that comes from the ignition switch module to the relay, I was finding a very low voltage coming to the relay. If you say you have power to the relay but it's not coming out, I'd recommend making a jumper wire to bypass the relay and testing both sides of the jumper while turning the key to see where power is or isn't.

 

thank you, how would i make this jumper to the relay? pictures would help

 

Make sure fuses are good and also the fusible link splices down on the starter are still good. I've had several 92s with the issue down there.

 

 

Go to the hardware or auto parts store and get your self automotive wire that is 10 or 12 gauge( should come in a packaged roll) and some insulated male spade connectors to fit whatever gauge wire you choose. Cut 4-5 inches of wire and use a wire crimper to place male spade connectors on each end.

 

Sorry for being late but thank you so much I will update if its successful

 

1 year later of diagnosing this issue and I think I finally got it. (I wanted to get away from my hotwire starting method).

Ended up doing another steering column rebuild in which I replaced the signal switch assembly and realigned the hi/low beam toggle and ignition switch.

after reinstalling, I tested the yellow wire coming off of the blue ignition switch harness to see if it would go to 12v while in start. It did. So I jumped the original wires back together and tada it worked. Now starts with a key. With that said. Enough changed to where I’m not sure exactly what fixed it (I know it’s not very scientific but it got the job done)

whoever said these circuits are simple is right. Keep trying till you get it.