Okay folks, I promise I've searched the threads for my specific VATS question and I haven't found the exact problem I am having...at least as far as I can tell.
I have a 1996 6spd LT4 CE
I changed out the starter because the starter motor went out (just got the click of the solonoid when I hit the starter). Now that I've changed the starter I have an intermittent VATS issue...I think. When I hit the key I get nothing but a small voltage drop on the gauge. I checked the clutch safety switch as best I can. With the key in "start" I pump the clutch and I get a voltage drop when I depress the clutch. Maybe that doesn't mean anything but it's the easiest test I could think of.
I saw an excellent post on checking the ign lock cylinder by checking the resistance at the wires under the steering wheel and my readings show that I'm within .02 kOhms from the resistance on the pellet on the key. The only thing I can think of that's left is the VATS decoder/module or whatever it is called itself.
So...1) I can't seem to find VATS decoders or modules for sale anywhere...any suggestions? and 2) Is there anything else that this could be and how would I check for it?

 

You may have a good clutch safety switch, but I would unplug it and jump the socket and measure the voltage on the jumper when you hit crank on the ign sw. You should see 12v on the jumper and the starter should crank. You can jump 12v to the jumper to prove that the starter solenoid and starter work. The resistance the VATS module sees must not exceed +/-4% of the assigned resistance value of your ign key pellet. Greater than 4% and no crank and you have to wait 6 minutes to try again. If resistance is ok, the VATS module closes the start enable relay completing the circuit to provide 12 v to the clutch safety sw and then through the firewall connector then to the starter solenoid. A defective relay coil or contacts won't allow 12 v at the clutch safety switch jumper. Another place to look is the battery cable connections. Remove the battery cables (neg first) and clean the cable lugs, bolts and battery terminals and replace the cables (neg last). Starter motors require 100+ amps and a very low resistance connection to the battery. Also, a rod goes from the ign lock down to the ign sw behind the dash and if that rod is not connected right or the ign lock is loose or ign sw is loose the ign sw may not make it to crank position. Let us know what you find, there are a few other places to look too.

 

I had seen something like this before about jumping the safety switch but I thought my voltage drop meant this wasn't the problem. I guess that's a little too simplistic. I'll pull that panel back down and see what I can find. Thanks a lot for your help.

 

Your dash voltmeter doesn't read the voltage on the clutch safety switch.

 

If it is the VATS I don't THINK you would see the voltage drop?
Maybe get a key cut WITHOUT the pellet and try it in the ignition and see if you still get the voltage drop?
If you don't get it, then that eliminates the VATS.

 

security light would be on in run position if it is vats related

 

i had that same problem with my 96 lt4 i replaced the key and it worked for a while. when it started to do it again i just eliminated the vats key by bypassing it with the wires under the dash. no more problems!

 

huh???

 

Have you checked the battery terminals and ground return. Almost sounds like you're not getting full and proper current to the starter. I would clean it all up for a starting point.

 

The Op said he sees a drain on the electrical system when he tries to start the car. This could be a bad starter trying to draw too much current or just a wire issue?
If the Key cut without the resistor does not give the electrical drain then the VATS system is NOT allowing the electrical system to try to start the car, no electrical drain=VATS is working the way it should and the problem is probably in the starter circuit?

 

Okay, I've taken off the leads to the battery and the starter, cleaned them and nothing. I've removed the hush panel under the dash and checked my resistance at the ign lead and I have the correct resistance with the key in the ignition. I haven't removed the clutch safety switch yet because it looks like a pain in the butt however if I hit the ignition without the clutch depressed I get no voltage drop on the digitial and analog gauges in the dash and the hood lights don't dim. I hit the ignition with the clutch pushed to the floor and I get a voltage drop and the lights dim. Jump-starting produces the same results.
There is no click from the solonoid so I don't seem to be getting anything to the starter. I pulled the starter and took it to a local shop and it tests fine. With the key in the ignition and the doors closed the security light is extinguished.
I'll try to get a test light on the small terminal of the starter to verify that no power is getting to it but do you folks have any idea what I'm going to have to replace to get her running again?
Sorry to be a pain but this has got me baffled.

 

first off, my knowledge of 'pisskey' (96 no longer used 'vats') is limited (on my desire)...but may i suggest:

remove 'hush panel', on underside of drivers side dash, above pedals...insert ign key, turn to 'on', set turn signal to l or r...follow turn signal flasher 'click' to flasher on firewall above clutch pedal...slightly above and to the right of the flasher you will see three relays (two identical, one not)...the relay furthest to the right is the 'theft deterrent' relay, aka 'starter enable' relay...verify relay id by checking wire colors into relay socket...two yellows, one yellow/black stripe, one purple should be seen...grab a new relay from napa/ dealer/etc (should be <$20)...unplug the connector and plug the new relay in (many Gm techs just leave the old relay in ol' home, 'dangle' the replacement, you decide)...note that fuel delivery is not controlled by this relay.

alternate test rather than replace the relay: check voltage in the relay socket pins of the two yellow wires (NOT the yellow/black) with key in 'start' and clutch pedal NOT depressed...one of the two yellow wire pins should should have +12v, the other 'o' v...verify by depressing clutch with key in 'start', both should have +12v... 'if' the yellow wire pin that has 12v present at this time were connected (jumpered) to the purple wire also serving the relay socket, the engine should crank solely on demand of keyed 'start' position (NOT recommended as this also bypasses the 'clutch safety interlock' switch)...


btw, no 'vats module' on 96, theft deter is done in the CCM using inputs from both the door alarm switche(s) module and pisskey (pardon spelling, actual title is copyrighted)

 

Folks, below is part of an exchange between myself and Redrose...hopefully a solution is forthcoming and I hope this thread might help someone with my level of ignorance of cars.

Okay, this is the first thing I've had that counts as progress. I took off the relay and jumped power from the larger yellow wire to the purple wire, and I hooked up a 12v test light to the starter solonoid post (the small wire connected to the starter). AFTER I jump the relay and I hit the starter the test light comes on so I'm getting power to the solonoid with the socket jumped apparently. However I don't seem to be getting the right amperage because the starter never engaged...I didn't even get the "click" of the solonoid.
I guess I still don't know exactly what is wrong but at least now I know I can get power to the starter...whether it's the right amount or not.
I must admit that I'm still a little lost as to what could be wrong.

 

If you have 12v on the starter solenoid (your test light lit up) and the starter solenoid doesn't click, then I would assume that you have a defective starter solenoid. It is confusing because your starter motor tested good wherever you took it. You can test the starter solenoid by connecting 12v to the starter solenoid terminal on the starter. This should cause the starter solenoid to pull in (click) and the starter motor should crank the engine.
Also, you do not have to remove the clutch safety switch. The wiring harness has two wires to a plug that plugs into the clutch safety switch. You can unplug the clutch safety switch and use a jumper wire connected across the two pins on the socket to eliminate the clutch safety switch. When you hit crank position on the ign sw, you should measure 12v on the jumper on the socket of the clutch safety switch and the starter motor should crank.

 

Ladies and Gentlemen, I come before you a humbled man. Hours and hours troubleshooting what I thought was a VATS, PK, starter, battery, wiring problem has taught me something. That first step in all troubleshooting that says "make sure the appliance is plugged in" isn't as dumb as I always made it out to be. While I was searching for some exotic computer problem I had shorted a the control wire to the starter solonoid. After pulling half the car apart I decided I would just go ahead and check every single fuse. The third one I pulled was fried...5 amp, clutch ign (I think that's what it was labeled). Replaced and the dang thing fired right up.
I would like to send a special thanks to Redrose who spent a lot of time sending me PMs and walking me through troubleshooting procedures. He kept me from spending a lot of money when I was sure it was the CCM. You are the man.
Thanks to all of you who posted answers to my question and I look forward to maybe having as much experience as you guys and helping some other poor guy out.

Thus endeth the thread.


Scrappy

 

Another satisfied customer.