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Old anti-theft device, Cat IV? Anyone heard of one?

Discussion in 'The Hokey Ass Message Board' started by vintagesurvivor, Sep 10, 2006.

  1. vintagesurvivor
    Joined: Mar 12, 2006
    Posts: 385

    vintagesurvivor
    Member
    from detroit

    Not a hotrod, but I picked up a 81 Vette. It has a "CAT IV" anti-theft box under the dash, and I would like to know if anyone ever had one or knows how to bypass it in some way? It has three tumblers with numbers 0 to 9 on them.
    The car does not start, though it turned over fine when I bought it. (I got a deal )
    It would pop a crackle, but it was parked 3 years, so the gas is crap, prolly 50 octane. Pulled the plugs, drying it out, put good new gas in, and going to pump out the fuel line to get better gas to carb. New plugs and wires. Should start OK.

    Wanna yank out / bypass the "CAT IV" if I can ....
    Help?

    Mark
     
  2. Toystoretom
    Joined: Feb 25, 2006
    Posts: 112

    Toystoretom
    Member

    If you take a close look at this Cat IV thing I'm sure you can figure out how to remove it. It is just simple electronic circuits, and you just need to break them down into separate circuits. There may be two wires that go to a hidden switch, just physically uninstall the switch. There may be two more wires that go to a horn or a siren, just cut those. There is probably a red power wire and a black ground.... cut those. There may be a relay or a motion sensor, if you have those just uninstall them also. Hopefull this should leave you with the brainbox that has the tumblers and maybe one or two wires that go to your ignition switch (or into your steering column). Take a look at these and you will see that when they installed this P.O.S. they cut some power or ignition wires and spliced this thing into the stock harness there. These stock wires may be red or white. Cut out the wires from the Cat IV and splice the same color wires from the stock harness back together. Before you do all of this be sure and disconnect the battery... don't burn your Vette to the ground.

    At this point pull the Cat IV thing out of the car and run over it, then pour gas on it and burn the remains...

    I wish I could be more exact but without seeing this thing its kind of hard. If you have a buddy thats good with circuits that would help alot. Basically you simply want to restore the stock wiring harness to its original condition. You should easily be able to tell the difference between the stock wires and this alarm box crap......

    Good Luck!!
    Tomo
     
  3. vintagesurvivor
    Joined: Mar 12, 2006
    Posts: 385

    vintagesurvivor
    Member
    from detroit

    Thanks for the help. If worse comes to worse I'll take it to the local auto-electric guy (he's fair), and have him undo it all.


    Mark
     
  4. DIRTYT
    Joined: Oct 22, 2003
    Posts: 3,264

    DIRTYT
    Member
    from Warren,MI

    the way it works is it interupts the start signal. All gm cars were the same wire color for years. There is a pink,purple,red. wire. red is constant hot.
    pink is start, and purple should be key on, Its been a while since i got into one but im preety sure thats what it is. yo can check with a test light. but your box should just splice the pink in half and jump off the purple. So just get under there and make sure those three wires are connected back up and it will fire up. pm if you want more help .. im being kinda vauge here
     

  5. vintagesurvivor
    Joined: Mar 12, 2006
    Posts: 385

    vintagesurvivor
    Member
    from detroit

    Thanks man, I'll let ya know, maybe you can square me away for a few $ :D
     
  6. to get it started find the power wire for the box, cut it, then find the signal wire going to the starter and re-attach it. after that you can remove the box later. it's not as hard as it sounds/looks.
     
  7. LarryinCanton
    Joined: Mar 15, 2015
    Posts: 1

    LarryinCanton

    I know this is a really old post, but I am curious if you were able to get the CAT-IV out of your vette? My grandfather designed and built these for years. Some of these previous posts would not have gotten your car started, there is no power in wire, etc. would love to know if your still have the CAT-IV you pulled out of the car. Thanks!
    -Larry
     

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