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Discussion Starter · #1 ·
This morning began with ignition woes on my 96 RMW.

a) In Park, turn key, gauges swing to right, silence
b) Put in Neutral, jiggle lever, foot on brake, turn key, gauges swing to right, silence

Situation a) has occurred in the past and b) has always worked as an expediency.

I have seen references to a key bypass/resistor mod, but Search has not been my friend. Lots of links made references to the mod, but have been unsuccessful at finding the link to it.

If anyone knows where this stickie is, I would appreciate it.
 

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Dirty key? One of my luckiest"repairs" for an intermittent no-crank was a Q-tip and windex on the key's oxidized/grimy resistor contacts.
 

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a) In Park, turn key, gauges swing to right, silence
b) Put in Neutral, jiggle lever, foot on brake, turn key, gauges swing to right, silence

Situation a) has occurred in the past and b) has always worked as an expediency.
A poetic statement. But hard to read and lacking the required parts of language common to just about every language in the world.

If someone told me that: When the starter does not work when I turn the key to start, I move the gear shifter around and the key will then activate the starter I would understand the problem much better.

The brake switch will not prevent the car from starting.

Edit incorrect: If moving the shift lever around will allow the starter to function the highest probability issue is the park neutral switch. See post #5:
The only car in this group that has one(park/neutral switch) is the 96 Impala , none of the others do.
Apology to the OP I have a floor shift. See my next post.


The "resistor fix" will not fix a problem with the basic starter circuit.
 

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Repeated mention of park neutral switches on this forum,,,
The only car in this group that has one is the 96 Impala , none of the others do.
They have a physical lock out that prevents rotation of the lock cylinder unless the car is in park of neutral.
They don't have a park-neutral switch
 

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b) has always worked as an expediency.
My translation is moving the shifter allow the key to actuate the starter.

Check that the key is switching the basic starter circuit. You can do this by checking for the key activation of the starter results in voltage at the crank fuse. If turning the key to start does not result in voltage at the crank fuse you will need to check the ignition switch and wiring.

The circuit diagram:

If shaking the shifter lever changes the results in a VATS issue consider changing the ignition lock cylinder. You can bypass the key resistor but 25 plus year old ignition lock cylinders may be mechanically worn out.
 

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Discussion Starter · #7 ·
A poetic statement. But hard to read and lacking the required parts of language common to just about every language in the world.

If someone told me that: When the starter does not work when I turn the key to start, I move the gear shifter around and the key will then activate the starter I would understand the problem much better.

The brake switch will not prevent the car from starting.

Edit incorrect: If moving the shift lever around will allow the starter to function the highest probability issue is the park neutral switch. See post #5:

Apology to the OP I have a floor shift. See my next post.


The "resistor fix" will not fix a problem with the basic starter circuit.
 

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Discussion Starter · #8 ·
Search VATS
I have, and repeatedly up comes a link to www.sofasst.com/pass_key_fault_fix.htm but that now links to a Japanese website.

Dirty key?
No, key was cleaned after second attempt, made no difference. Am unwilling to stick a Q-tip or any other object into the ignition switch given the possibility of making things worse.

Check that the key is switching the basic starter circuit.
Turning the key causes a significant drain on the battery (gauges swing to right), and near flattened the battery. I am blaming the resistor because as I understand it, that is what prevents starting.

The "resistor fix" will not fix a problem with the basic starter circuit.
There is no problem with the starter circuit. The car started this morning, the bypass resistor fix will eliminate the key and ignition as issues.

I have found Pass Key resistor mod which modifies the male connector from the steering wheel side to include the correct resistor value.

Youtube has also been useful e.g.
www.youtube.com/watch?v=3PkHTxDQpkE
www.youtube.com/watch?v=Z-sWFS8WZ3w

Between them I feel confident of being able to implement the bypass. As I remember from high school, running resistors in parallel reduces the max so to match 681 Ohms I use a 1K and a 330 soldered together and for 1130 Ohms I use a 1K and 120 soldered end-to-end.
 

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Turning the key causes a significant drain on the battery (gauges swing to right), and near flattened the battery. I am blaming the resistor because as I understand it, that is what prevents starting.
The VATS system will not "flatten" a battery.

Even with the HVAC blower on high a battery in good condition will support leaving the key in the run position for 15 minutes or more and still have enough energy to start the car.

A bad battery can cause various computerized systems on the car to malfunction. The VATS is such a system.

You have not posted if the VATS light has been on while your are driving. You have not affirmed that the VATS light is on when the starter will not function.

gauges swing to right)
When the key is turned to the "run" position the car does a "bulb test" this includes lighting all warning bulbs (VATS as well) AND forcing the temperature gauge to the right. The gas gauge is powered and will register an actual reading (when off it shows a random value). The voltage gauge is also activated and will "swing right" to show system voltage.

I can not say you do not have a VATS problem but you have yet to provide any information that demonstrates a symptom. You have described a battery problem and possible ignition problems.

The VATS light being on after the bulb test would be a symptom. Testing the crank fuse when the starter does not activate is a test.

Before doing the "resistor mod" you could use a ohm meter to test the key in the ignition. They are the two wires you want to cut without testing.
 

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As I remember from high school, running resistors in parallel reduces the max so to match 681 Ohms I use a 1K and a 330 soldered together and for 1130 Ohms I use a 1K and 120 soldered end-to-end.
So many issues here.

One car has only one key resistance. Which is it 680 Ohms or 1130 Ohms?

If it was 680 Ohms why use two resistors when 680 Ohms is a standard value?

1000 ohms and 330 ohms result in 248 Ohms in parallel or 1330 Ohms in series. Never 680 Ohms.

If you get 1% resistors instead of the normal 5% a 680 Ohm resistor can be 687 to 673 Ohms(1%) The error can be worse if you use more resistors or 5% resistors. The VATS should work with this range and even more error in the resistance.

For your 1130 Ohms choice: Between the 1-5% resistor tolerance (error) and your 27 year old VATS module (may not be perfect) you might have to try either 1000+100 or 1000+120. As the car is exposed to extreme hot and cold one of the two choices might cause a VATS problem.
Worst case 5%
1100=1155-1045
1200=1260-1140

Over the years reputable manufactures have kept the 5% resistors very close to advertised values. But some of the no name flea bay specials I have seen are at, or out of the 5% range.


I feel confident of being able to implement the bypass
I and others( I hope) wish you the best but these simple fixes are not always simple.
 

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Discussion Starter · #14 ·
This unit is the easiest way to do the VATS bypass but also the most expensive.
Great product if you do not know your key's resistance.

...why use two resistors when 680 Ohms is a standard value?
Because I had a box of resistors from long ago, and took a few to see what I could get. Obviously forgot how to calc parallel resistance, so thanks for that.

Combining advice from both of you, have ordered a pack of the correct values for $8 from ebay.

This unit is the easiest way to do the VATS bypass but also the most expensive.
Great product if you do not know your key's resistance.

...why use two resistors when 680 Ohms is a standard value?
Because I had a box of resistors from long ago, and took a few to see what I could get. Obviously forgot how to calc parallel resistance, so thanks for that.

Combining advice from both of you, have ordered a pack of the correct values for $8 from ebay.
 

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Update: Found PASS KEY FAULT?

Stopped by junkyard and clipped the two white wires with connector from the steering wheel. Soldered the resistor between white wires, unplugged connector under dash, and plugged in the bypass.
And did this fix your problem? Or are you still having trouble?

Not sure I would admit to bypassing that security feature on a public forum. There's a reason GM added that technology. But whatever. Good job for not cutting wires so it could be easily reversed.

FWIW, I know for a fact that cars with column shift do indeed have a neutral safety switch. Not only is it shown in the FSM, but anybody can confirm this by getting in the car. Key and engine off. Then turning the key to run (without starting). Then move the shifter to D. Then try to start it. No crank. I probably would have started there based on your original description. But if the VATS bypass solved it, then it's all good.
 

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Discussion Starter · #17 ·
And did this fix your problem? Or are you still having trouble?
So far so good, but it was an occasional glitch so will be a while before I feel fully confident.

FWIW, I know for a fact that cars with column shift do indeed have a neutral safety switch.
I thought the neutral safety switch was the issue until the car would not start in either Park or Neutral/brake. That was when my focus moved to VATS.
 
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