Engine won't crank, not VATS, clutch safety switch, battery

**318Charger** · 09-05-2010, 01:09 PM

Hello there. I have a 1998 firebird formula with the LS1 and a 6 speed manual. I was driving it last night, shut off the engine, went into a friend's house for 5 to 10 minutes, then came back out and it wouldn't start. All the electronic systems started up as normal when turned to the on/ignition position. However, when I turn the key to the start position, nothing. No clicks or anything.

The car will still run. Luckily, we were at the top of a hill and I had guys with me to push start it (thank God for manual transmissions!). Got er rolling fast enough then let out the clutch in second with the key in the on position. It started right up and ran fine, so the problem isn't an alternator or battery.

It's not the Anti theft system with the resistor in the key. I went to radio shack today, measured the resistance to find the correct value of key, and then bought the corresponding resistors to hook up in series and get the right value, or a value that should be close enough to make it work.

It's also not the clutch safety switch, which was my second guess. I took it loose from the bracket and tried to start the car with the button both pushed in, and not pushed in. Neither worked. I unplugged the switch from the wires and tried to start it. I then took a wire and closed the circuit and tried to start the car. No luck with any of that.

All the fuses on the car, both on the side of the dash and under the hood, are good. None are blown. I had a friend turn the key while I was under the hood. When he turned the key to the on position, I felt the ignition relay click. But when he turned it to the start position but I felt no click from that relay. This leads me to believe the problem is either before starter relay or the starter relay itself, which rules out anything such as the starter being bad or the solenoid on the starter being bad.

One last piece of information. I was messing around with the clutch safety switch while plugged in, switching it on and off while trying to turn the key. It started up once and ran fine, then when I shut it off and tried to start it again, nothing happened. When this happened, the resistors I got from radio shack were not plugged into the wiring harness, giving even more proof that it's not the VATS system.

So here's my question: What else could it be? If it is a short in the wiring or a bad connector, does anyone have a wiring diagram of the starter system so as to adequately troubleshoot where it could be?

Thanks in advance.

**KMdef9** · 09-05-2010, 02:06 PM

Ignition relay

**318Charger** · 09-05-2010, 02:26 PM

Well, I said in my post the when the key is turned to the on position, the ignition relay clicks on.

**DaddySS** · 09-05-2010, 04:45 PM

Originally Posted by 318Charger

Well, I said in my post the when the key is turned to the on position, the ignition relay clicks on.

I would swap it and the starter relay too - the relays are interchangeable so it's a quick check.

**318Charger** · 09-05-2010, 06:10 PM

So the two relays are separate of each other? If I don't have the ignition relay in, it will still crank, it just won't start?

**Cutlass** · 09-05-2010, 07:27 PM

here ya go

**89RS&98Z28** · 09-06-2010, 06:24 AM

Just for the sake of asking does the security light come on or not?

**318Charger** · 09-06-2010, 09:18 AM

the security light comes on for two or three seconds and then shuts off.

**jad628** · 09-06-2010, 10:43 AM

I had the same thing happen on Saturday. I went back and tried to deduce what it was, and here is my best "guess":

At the grocery store, I went to put some stuff in the trunk and opened it with my key (the trunk release on the FOB isn't working), however I forgot to unlock the doors first and set off the alarm. I hit the unlock button ONCE (not twice to unlock both doors), and then ran the buggy back to the store. I got in the car, turned the key, nothing. Removed/inserted, re-inserted key, still nothing. Windows worked, radio, headlights, etc. After about a minute, I took the keys out and hit the unlock on the FOB twice to unlock the passenger door. Re-instered key and the car started fine.

I summized that my problem was linked to the security system.

**KMdef9** · 09-06-2010, 11:07 AM

Originally Posted by 318Charger

Well, I said in my post the when the key is turned to the on position, the ignition relay clicks on.

Hearing a clicking noise doesn't mean it's working.

Originally Posted by DaddySS

I would swap it and the starter relay too - the relays are interchangeable so it's a quick check.

+1. And cheap. And common.

Originally Posted by 318Charger

So the two relays are separate of each other? If I don't have the ignition relay in, it will still crank, it just won't start?

Shouldn't crank.

**Cutlass** · 09-06-2010, 02:12 PM

Originally Posted by KMdef9

Originally Posted by 318Charger

So the two relays are separate of each other? If I don't have the ignition relay in, it will still crank, it just won't start?

Shouldn't crank.

Actually it should crank just fine with out the ignition relay, assuming the starter relay is ok. It just won't start because the ignition relay powers up the fuel injectors and ignition coils among other things.

**Too Fast** · 09-06-2010, 02:26 PM

Before you go about checking all the wiring that goes to the started, do a simple check for power at the small wire at the startet.

Have a friend put the car in the crank position, and check for ~12 volts there, then. If you have a 12v signal to the starter small wire while the ignition key is in the crank position, your starter is bad. If not, then do the harder stuff like looking at wiring diagrams and see where you lose the 12v signal to the starter solenoid.

**Cutlass** · 09-06-2010, 02:57 PM

Originally Posted by Too Fast

Before you go about checking all the wiring that goes to the started, do a simple check for power at the small wire at the startet.

Have a friend put the car in the crank position, and check for ~12 volts there, then. If you have a 12v signal to the starter small wire while the ignition key is in the crank position, your starter is bad. If not, then do the harder stuff like looking at wiring diagrams and see where you lose the 12v signal to the starter solenoid.

^^^That is also how I would approach since the starter is likely problem. This would be my 1st step.

**318Charger** · 09-06-2010, 03:27 PM

The starter is not the problem. I and a friend were working on it all of today. We were able to jump the starter with a wire and it cranked. It's definitely not the relays either. I switched the starter relay with the ignition relay and no dice. We then jumped the terminals on the starter relay and it started right up. We then measured the voltage across the two terminals that actuate the starter relay and they were about .08 volts. So for some reason this circuit isn't getting enough juice. It's a yellow and black wire and we don't know where it comes from. We had an inkling and looked at some wires on the body control module. There was a yellow and black wire on the connector there and we measure the voltage across it and a ground and it was also .08 volts. So my question to you guys is, what wire going INTO the body control module corresponds with this yellow and black wire coming OUT of the body control module? I'd like to be able to measure the voltage across it to find out if the problem is before the body control module or after it. This means the issue is somewhere between the clutch switch and the BCM.

**KMdef9** · 09-06-2010, 05:03 PM

Originally Posted by Cutlass

Actually it should crank just fine with out the ignition relay, assuming the starter relay is ok. It just won't start because the ignition relay powers up the fuel injectors and ignition coils among other things.

Meant to put a question mark at the end of that, thanks for the catch! (What I get for not proof reading things at times)

To the OP I have heard of the BCM being problems in our cars. Not sure if the whole thing gets replaced or not. I'm digging through some wiring diagrams for the BCM, but can't find one, yet.

EDIT: The only wiring diagram I have that even mentions the BCM is the same one that cutlass provided, sorry.

**Too Fast** · 09-07-2010, 05:39 AM

There is no wire going back out.

The BCM grounds the yel/blk wire, to enable the starter relay, when other correct conditions are met (like the VATS signal). If you have B+ at the yel/blk, at the BCM, when trying to crank, that means all is good there, and your BCM is likely bad. Sounds like you proved the other part of the circuit by jumping across the starter relay, to get it to crank that way.

Sounds like your BCM is bad, if all the above testing is done correctly.

If you don't have B+ at the yel/blk, while trying to crank, see if you do back at the dark green, at the clutch switch. If you don't have power there, while attempting to crank, then check for power at the pur/wht at the clutch switch. Do all this checking with the wiring intact, backprobing. If you disconnect things, you have to check voltages in a different way.

Let us know what you find. G/L!

**318Charger** · 09-07-2010, 01:44 PM

Okay guys, I feel like an idiot for wasting my time and yours. Last night after talking to my father, I found out that I was looking at the wrong "clutch switch." I couldn't figure out why the clutch switch would be in series with a switch on the brake, so I talked to my dad and he suggested it was probably to disengage the cruise control. I didn't even think about this! My cruise control doesn't work, so I guess I'd completely forgotten it was there at all. Today, I went to go and look for the correct clutch switch that was wired to the starting circuit. I located, took the connector loose, closed the gap with a piece of wire, and lo and behold, the car started. So I guess it was the clutch switch all along. Sigh. So my next question is, does anyone know what the part number for this switch is and where I could get one at? Would any of the major auto parts stores (o reilly's/auto zone/napa/etc) be able to order in this switch, or will I need to go to a GM dealership? Or would it be cheaper online? Thanks so much for all the help guys! I really appreciate it!

**Too Fast** · 09-07-2010, 04:21 PM

Originally Posted by 318Charger

Okay guys, I feel like an idiot for wasting my time and yours. Last night after talking to my father, I found out that I was looking at the wrong "clutch switch." I couldn't figure out why the clutch switch would be in series with a switch on the brake, so I talked to my dad and he suggested it was probably to disengage the cruise control. I didn't even think about this! My cruise control doesn't work, so I guess I'd completely forgotten it was there at all. Today, I went to go and look for the correct clutch switch that was wired to the starting circuit. I located, took the connector loose, closed the gap with a piece of wire, and lo and behold, the car started. So I guess it was the clutch switch all along. Sigh. So my next question is, does anyone know what the part number for this switch is and where I could get one at? Would any of the major auto parts stores (o reilly's/auto zone/napa/etc) be able to order in this switch, or will I need to go to a GM dealership? Or would it be cheaper online? Thanks so much for all the help guys! I really appreciate it!

Glad we could help. You should be able to get that switch at just about any parts store. I guess I forgot to remind you that there are 2 switches on the clutch, one for the cruise and the other for the starter.