Yep - I've got your answer!

Neutral Safety Switch!

In the diagram ... key to start position, 12v+ sent via a yellow wire to Starter Enable Relay, which sends 12v+ to the Neutral Safety Switch on a dark green wire, the Neutral Safety Switch Iif in Park or Neutral) then sends 12v+ out on a purple wire to the starter solenoid on the starter.

Neutral safety Switch is under center console, two screws hold it to the right side of the shifter plate. There's a plug on the front side with 5 wires - one is that dark green, other is the purple. New switch $35 at CarQuest.

Can test the theory again by connecting a lead to the same terminal the purple wire connects to on the starter, and bumping that wire to the positive battery terminal - with key off, starter will turn, but car won't start (with key on, car will start and run).

That purple wire must have 12v+ in order for the starter to crank.

I just this weekend had this issue and just got my new Neutral Safety Switch tonight - will be installing in the morning.

 

ok, i tested the wire at the neutral safety switch, the green wire, and its 12 volts at the switch. i am going to try the wire from teh starter to battery and see what i get. I dont think its the switch though because when i had the B&m shifter in the car, i had the same problem.
Is it possible that when I put the B&m shifter in that one of the wires got messed up. I have since put the original shifter back in the car and made sure the wires to the shifter are secure and they have good connections. Where does the purple wire at the starter go to before it goes to the shifter? I am thinking somewhere in that line there is where the problem lies.

 

Purple wire leaves neutral safety switch and goes directly to starter solenoid.

You've already stated you only had 6 volts on the purple wire at the starter, and you're getting 12v on the green wire that goes into the netral safety switch, so it must be the neutral safety switch.

I guarantee that if you apply 12v to that spot where the purple wire goes to the starter, it'll start every time you do it.

 

ok im going to try that, i hope it works and i can fix this problem.

 

easy test is use a jumper wire from the Neutral safty switch connector i.e. jump the green connector to the purple one and see if the car starts

 

Not true. The purple wire goes to the C100 bulkhead connector in the driver side corner of the firewall. Wouldn't be the first time that connector had a problem.

Not sure about '91, but earlier years the wire from the ignition switch to the neutral safety switch was yellow. Is this green wire with 12v the same size as the purple wire? Does it only have voltage when the ignition is in the "start" position? Again, for earlier years, the green wire was for the back-up lights, and has 12v any time the ignition is on.

 

Yes the green and purple wire are the same gauge, the green as you stated is for the backup lights if i remember correctly. What should be my check for the purple wire, should i trace it back to under the steering column? What should the voltage be to that wire 12v? Would this cause the problem I am having with my starting issue, or is this a seperate problem?

 

The back-up light wire is much smaller than the purple wire.

The purple wire won't go back to the steering column. It goes from the neutral safety switch to the C100 connector. Unless it changed between 1986 and 1991, the wire from the ignition switch on the column should be yellow.

The voltage on the purple wire at the starter should be close to battery voltage. It isn't unusual for there to be a little drop, but it should be within a couple of volts of battery voltage.

I had a one volt drop across each of the ignition switch, neutral safety switch (the microswitch that came with the Mega Shifter), and C100, resulting in no-starts when hot. I installed a remote starter solenoid 3 years ago and haven't had a no-start since.

 

On my 1992, the green wire is as large as the purple wire. On my 1992 there is a yellow wire runs from the ignition to the starter enable relay, then the relay runs that green wire (which is nice and thick) to the neutral safety switch, then the purple wire runs from there to the starter.

Might be in the bulkhead - I just meant that is doesn't run to any other switches or relay from the neutral safety switch to the starter.

The purple wire will only get 12v when ignition is turned to start.
Green wire only gets 12v when the ignition is turned to start.
{at least in my 1992}

 

yep i got 12v with the green wire but not the purple wire. i am going to double check it again. what exactly is the c100 connector and where is it located?

 

Ah, forgot about VATS.

Sorry.

The C100 is in the driver side corner of the engine compartment/firewall. Above your left foot when sitting in the driver's seat.

 

Question to five7kid: where did you get the remote starter solenoid? how hard was the installation? ive been having this same problem on my 91 rs with a 5 speed. i thought that the remote solenoid would fix it but i cant seem to find it anywhere thanks

 

is there a way to test the c100? what does it look like exactly? If all else fails I may look into the remote mounted solenoid as well, but have no idea where to begin with that setup.

 

five7kid, i looked at the remote solenoid you got from summit, it looks easy enough to install. My only concern is by doing that i am still neglecting that i have a problem somewhere and i am just temporarily avoiding the underlying issue.

 

So did you try replacing the Neutral Safety Switch yet?

 

I havent purchased one yet, havent gotten in the garage since saturday. I am going to check the wiring one more time before i purchase anything. My main concern with the neutral safety switch being the culprit is the fact that when i had the B&m shifter it had its own neutral safety switch mechanism and even then i had the same starting problem. So unless the neutral safety switch from the B&m shifter was faulty and this current one is also faulty i am skeptical. But if i dont find anything in the wiring i will buy another switch and see what happens.

 

checked wiring again at the shifter and I got between 7 and 8 volts at both the green wire and the purple wire. took the underdash apart under the steering column but dont know where either one of those wires goes. i checked the battery voltage to make sure it was holding a charge and it was at 12.55 volts.

 

Well, I just finished mine today - but doubt my success will help you much unless you want to drop the same $120 I just did.

I installed a mini-starter and the new neutral safety switch, gave my battery a good charge after playing with the doors open and the radio on all day, and she cranks right up every time - something my car hasn't done in a long while.

 

at this point all i would need is a new neutral safety switch and I will have the same setup as you do. the way things are going it looks like i will be buying a new switch too.

 

bump

 

todays progress or lack there of consisted of changing the ignition switch. well now i have a new problem, the car wont even click when i turn the key. I am assuming that the new ignition switch is just miss adjusted which is why im getting nothing. Did i miss something while changing the ignition switch?

 

Did you get the new keys for the new switch cut with the resistor value from the VATS pellet in the old key? Your VATS is looking for that resistance value from the pellet of the ORIGINAL key.

I too am still having issues. I thought I had it licked, started just fine the last 15 or so times, and today ... BAM! I can start it, but not always from the ignition - I have to turn the key on, pop the hood, and apply 12v+ to the starter where the purple wire connects. So I too am still at a loss - thought I had it licked with the new Neutral Safety Switch

 

I am a little lost, i didnt know that the resistor in the key needed to be changed if you replaced the ignition switch. I didnt replace the ignition lock cylinder if that was what you were thinking, just the switch that sits down on the column.

 

Oh - if you didn't change the part that the key goes into, then it should be fine then - sorry. I just went out a bit ago, and mine cranked up again - so, like you, I'm having a mystery intermittent issue still.

I'll keep hunting ideas ... meantime I'll resort to the reality that I just need to keep a 4ft chunk of wire with me to jump the purple wire at the starter from the battery.

 

ok phew, I think i just didnt have it adjusted correctly when i installed it. If you come up with any solutions let me know and when i find the problem i will do the same. out of curiousity, what voltage do you have at the neutral safety switch for both the green wire and purple wire?

 

I get 12v on the green, but only 8v on the Purple - this is when the key is turned.

 

Camarorsssss: have you checked voltage at the starter relay? It sounds like you are losing voltage somewhere. I would follow the wiring diagram and check your voltages back from the neutral switch until you find where your voltage drop is.

Camaronewbie: Are you checking the voltage directly at the neutral saftey switch? If you are and the voltage is dropping from one side to the other it may not be engaging completely.

 

Where is the starter relay located? I had planned on doing just that once i get the new ignition switch set up properly. I wanted to trace the wiring back to find the problem but was a little stumped on where exactly the wires come from before going to the neutral safety switch.

 

I think it is behind the driver side kick panel, mine is an 84 so I'm not 100% because I don't have the relay

 

i thought there wasnt a starter relay?

 

Look on your diagram on page 1, it's called the starter enable relay. It shows it as a tan/white wire that runs out of it but it my Haynes manual it says tan/white or dark green. It goes from that relay to the neutral saftey switch.

 

That should be your green wire into the saftey switch. Check that the yellow wire into the relay has battery voltage with the key in the start/crank position. Also check that the pink wire into the relay and the black/yellow wire out have battery voltage with the key in the run and the start position. If you are not getting battery voltage at the relay then you will have to keep moving back along the circuit to the ignition switch and check power in and out of it.

 

Ill take a look and see what i find

 

Well - I know my starter enable realy is working, because 1) I hear it click with my big head up in the dash, 2) I'm getting voltage on the dark green wire at the neutral safety switch.

What baffles me is the intermittent-ness of it. After a few more days of playing, it seems like it doesn't want to start hot - after a few hours cool-down, it seems to crank fine - until it's warmed up again. But this is a brand new starter, and a mini, so it has alot more clearance between it and the headers. And, there's been a few times it just clicked when it was cold as well - so that theory of heat isn't a very good one - it just definitely never starts hot, and maybe or maybe not when cold.

The wires to my neutral safety switch have been cut and butt-connected by someone else in the past - so I'm going to try connecting the green wire directly to the purple and see what happens - they are both the same guage so that won't be an issue. That will take the neutral safety out of the equation, and if it still acts up, then I'll try a new relay - just because the relay clicks doesn't mean it's always getting or giving enough voltage.

 

how do you test the relay is my question?

 

I disconnected the purple wire on the starter, then flipped the key to start with my head under the dash, and I could hear it click. I also checked the voltage on the green wire at the neutral safety switch when the key was turned, and got 12v there. But I'm only getting 8v coming out on the purple wire (at the neutral safety switch).

 

do you know how a relay works? if you don't it's ok... I just learned how they work recently... ... a relay in order for it to work needs two power sources ... one 12v and one 12v-ign source... the other two connections are for ground and to the component...

 

To test the relay, pull it out and and it should have a diagram on it somewhere. Something like this:

87-/-30
85-Z-86

Basically you energize 85 to 86 and it closes 87 to 30. So take 2 jumper wires and hook one to your battery positive an the other to your battery negative, then hook the + to post 85 on the relay and the - to 86. Then take your ohm meter and check from post 87 to post 30. With power to the relay you should have 0 ohms between 87 and 30.

 

If you have 12v at the neutral safety switch then your relay is probably fine. The other guy doesn't have 12v to his safety switch. I'm guessing that if you jump the green to the purple it will start fine. It sounds like the problem is in the safety switch or possibly the gear selector if it is an automatic.

 

actually the second time i rechecked the voltage at both the purple and green wires at the shifter i got 7-8 volts not 12 volts, so i am narrowing it down to somewhere before teh neutral safety switch, so that means it could be the relay or somehwere between there. But I have to fix the new ignition switch and get it adjusted properly first. if anyone has any hints to doing this i am all ears.

Well i can rule out the ignition switch as the problem, re-adjusted it and back to the same old thing. Hook up the battery charger and bang starts up, no charger=no start. If the starter relay was malfuntioning, wouldnt it still not start regardless if I added the battery charger? When relays fail isnt it all or nothing?

 

bump

 

Well, after playing with everything AGAIN, I've come to the conclusion that (for me anyway), it HAS TO BE the neutral safety switch (NSS). Even though the one I have is only 6 days old, it must be bad - it wouldn't be the first time I've gotten a brand new bad part. I am always getting 12v on the dark green wire coming from the starter enable relay to the NSS - always - so the starter enable relay is good, period. I only ever get 8v out of the purple wire - I never get 12v out of it. But - If I run 12v directly from the battery to the purple wire AT THE NSS, then the car always starts, always! So, it just has to be a bad NSS for me. I've ordered yet another one to try tomorrow - will update.

 

I hope you get your problem solved, i wish mine was that easy. I ve narrowed it down but still no definitive answer . I am not looking forward to tracing my wiring back from my neutral safety switch.

 

Wow, I am having the exact same kind of problem. My car started this winter when I was trying to sell it, and now it will not start. I put in a new starter, no dice, charged the battery, no dice, checked all the fusible links- found one bad one and replaced it, no dice. I found my starter enable relay, it is behind the kick panel that encases the hood release, it is under some black goo.....mine is working or seems to be. I pulled the gear shifter cover, and pulled the plug from the neutral safety sensor and jumped the green and purple terminals, no dice........So, i am looking at the ignition switch tomorrow and the gear selector switch for problems. I do have a suggesttion for the couple of people having problems- replace all the fusible links at the starter area and at the radiator near the battery, there is a terminal block on the side of the radiator next to the battery. We may all be suffering from a high resistance short- this occurs when the conductor wears or corrodes away and goes down in diameter, which stops all the neccesary voltage from reaching its intended place, but will still allow some voltage through. Will let you know how it goes tomorrow, I am going to cut and replace all fusible links then, should be like 6 all together. My wires that formerly went to the Vats anti-theft system get super hot and smoke a little during cranking attempts, but the motor will not crank. Any ideas? Please help? Also, does anyone know exactly where the engine ground strap is located? I want to make sure I have a good ground but I can't seem to find it. I have a 91 camaro Rs w/ t-tops, a 305ci, driven by a 700r4. Any other ideas would be appreciated......

 

Replace the starter enable relay. Its only like 5-10 bucks and a relay is a kind of part that can work sometimes and other times not work at all. Its got a small electro-magnet and small contacts inside of it that can cause it to work differently depending on battery voltage, temperature, where the contacts touch, etc. There is quite a bit going on in that little relay.

 

my relay is definitely working, i removed the cover and looked at it and operated it via the key with the cover removed, but I may replace it just so everything is new again. the guy at advance auto parts said he does not carry it and its not in the computer, any ideas on where to get it for 5 or ten bucks?

 

I am having a hard time finding a replacement starter enable relay as well, couldnt even find it on rock auto

 

are you sure it's not a multi-use relay? I think all relays work in the same way... only difference is the housing itself...

 

Well, NAPA didn't ship my NSS today, so I have to wait til tomorrow.

Ground strap should be back of pass head, connects to firewall beside blower motor. Neg batt wire to front of pass head. Another smaller Neg batt wire connects to fenderwell behind battery.

 

I will look at it again, but it didnt look like the fan or fuel pump relay. I will see what i can find out about it and take a picture of it.