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VATS bypass help requested

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Old Apr 29, 2006 | 08:49 PM
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Default VATS bypass help requested

My '95 SE has the no crank problem, security light on. I've read the previous threads on the same subject.

I've cleaned the key chips and ignition switch internals with rubbing alcohol. Right now, after a few tests, things seem to be OK (hope it stays that way).

Questions:
1. How do I get the resistance readings on the key chips?
I put the clips from my multi-meter on each side of the key, on the chips. No reading. Put one clip on the key away from the chip, other clip across chip. No reading. What is the correct procedure?

2. In case things go bad again, and I need to bypass the VATS, exactly where do I install a resistor. Apparently the wires are inside of an orange sheath under the dash, wires probably white. Do I cut one of the wires, which one, and splice the resistor into that wire? Or, what is the correct procedure for splicing in resistor?

Thanks for any help.

Dave
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Old Apr 29, 2006 | 09:33 PM
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To get the resistance, put one probe on each side of the chip on the metal contacts. If you are getting no reading, there may be a problem with the resistor chip in which case a new key is the easiest fix. If you do get a reading (there are I believe 5 possible readings, but I don't remember what they are off hand) and you want to bypass the system, you need to build a resistor of the same resistance as the chip. I used some cheap resistors from Radio Shack for this. Once you have done that, remove the dash panel under the steering wheel and find the wires going to the ignition. They are 2 hair thin wires inside one sheath that connect to contacts that touch each side of the key, when the system works. To splice in your resistor, cut both wires and attach one wire to one end of the resistor, the other wire to the other end of the resistor. Secure everything so it can't move inside the dash, button it back up, and you should be done.
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Old Apr 29, 2006 | 10:07 PM
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Thanks for the answer from TheEngineer.

I tried for a resistance reading again on my keys chips. I didn't get a reading until I was on the 20K scale. I got a reading of 2.97. Does that mean the actual reading is 20,000 x 2.97 = 59,400 Ohms? So I would need a resistor of approximately 60,000 Ohms?

If I cut the 2 wires to install a resistor at the ends of each cut wire, what happens to the other ends of the wires where they're cut? They much go someplace. If I cut them, wherever the current was going, is not receiving the current anymore. I've just got 2 cut wires. Installing the resistor is just making a loop for the current going back to the ignition switch?? Am I missing something here?

Forgive me if I'm asking stupid questions, electricity and electrical circuits are a big weak point with me.

Dave
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Old Apr 29, 2006 | 10:42 PM
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If I cut the 2 wires to install a resistor at the ends of each cut wire, what happens to the other ends of the wires where they're cut? They much go someplace. If I cut them, wherever the current was going, is not receiving the current anymore. I've just got 2 cut wires. Installing the resistor is just making a loop for the current going back to the ignition switch?? Am I missing something here?
Just tape the ends going up the steering column and let them lie. that'* what i did. The resistor is wired into the end with current flowing.

Here'* the link I used. As above, i got the resistors at Radio shack, 5 for a buck. Took ten minutes.

http://www.12vp.com/info_resistors.htm
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Old Apr 29, 2006 | 11:09 PM
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Just tape the ends going up the steering column and let them lie. that'* what i did. The resistor is wired into the end with current flowing.

Here'* the link I used. As above, i got the resistors at Radio shack, 5 for a buck. Took ten minutes.

http://www.12vp.com/info_resistors.htm
Bill,

Thanks for clearing things up for me and the web link.

Dave
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Old Apr 29, 2006 | 11:11 PM
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Bill,

Thanks for clearing things up for me and the web link.

Dave
Sorry, I meant Bob.
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Old Apr 30, 2006 | 12:15 AM
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Originally Posted by ssewannabe
Thanks for the answer from TheEngineer.

I tried for a resistance reading again on my keys chips. I didn't get a reading until I was on the 20K scale. I got a reading of 2.97. Does that mean the actual reading is 20,000 x 2.97 = 59,400 Ohms? So I would need a resistor of approximately 60,000 Ohms?

Dave
It means 2.97 KOhms which is about 2970 ohms. Your resistor chip is the ~3010 ohm variety.

http://www.asttraining.com/Files/vats1.pdf

Build a resistor within 5% of that and it will work.

I made these diagrams to get an answer to where to put the resistor when I was doing this, Idea #2 is correct.

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Old Apr 30, 2006 | 12:52 AM
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Thanks for the info TheEngineer, appreciate it!!

Dave
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Old May 4, 2006 | 06:23 PM
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Thanks to Bob Dillon and TheEngineer for the detailed info on how to install a resistor in the VATS circuit so my car would start. It'* been a few days now and everything seems to be working OK now.

I was having intermittent problems with the car not cranking, and the security light coming on when trying to start the car. I tried cleaning the chip on the key, and the reader in the ignition switch with rubbing alcohol with occasional luck. It was getting so the car would not crank more times than it would when I tried to start it.

I wound up soldering 2 - 1,500 Ohm resistors between the two small white wires going up to the key chip reader in the ignition switch.

This forum has the people with the knowledge who are willing to share that knowledge to help others. It'* great. Thanks again guys!

Dave
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Old May 5, 2006 | 11:16 AM
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Sorry, but for the record, only IDEA #2 will work.

IDEA #1 won't work if there'* a resistor chip in the key. If you use this modification, when a key is inserted into the ignition, the resistor that you added in-line with the wire will then be in series with the resistor chip in the key, and the 2 resistance values will be added and the total value will be incorrect.

Idea #2 will work regardless of the resistor chip value in the key, and even if there'* not a resistor chip in the key.
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