Hi i just joined this site and was wondering if anyone could answer my question on the vasts system,i know there are some posts on here about this but they don't answer my question.Here goes,I have a '89 Trans Am GTA with the 350 motor,when i bought it there was only a standard type ignition key and there was some kind of home made bypass system installed by taking wiring from the starter motor to a switch on dashboard.I have removed all the wiring as i am tidying engine bay but my problem is how to sort the vats system.As i don't have a vats key available is there any other way of finding out which vats key i need.I have been told by a american car dealer over here in England that they can find out for me but it is expensive and i need to take car to them,but that is not possible at moment.If i buy a vats module and matching key would this sort the problem of having no vats key,or will i still have same problem or is it easier to buy a vats bypass module,i don't want anything that looks untidy.Thanks for any help.

 

LT1 Swap has a good write up on identifying what resistor value you need for your key. I'd buy a bunch of the appropriate resistors from his chart at Radio Shack and see which one made the VATS happy. Then you will know which of the 15 key blanks you need to buy.
This assumes your steering column still has a VATS key cylinder in it.

 

^Exactly. The resistors are cheap, and there's only 15 possibilities.

If you don't have the VATS key cylinder in the car, you can always solder them up to some wire and plug the resistors into the passkey socket at the base of the column.

I've become a bit familiar with the underdash wiring in the past couple days... It's starting to drive me

 

Sounds to me like the vats has already been bypassed, somebody wired a resistor across the vats module wiring. The connector is under the dash near the steering column, find that resistor and measure it with an ohm meter, that will tell you what resistance your key should be. Assuming you want to put it back to stock. That means changing the lock cylinder and fishing the wires down the column.

Personally, if it works, I'd leave well enough alone and get a decent alarm system.

 

Hi thanks for replies i will try the stuff you have all told me.I am not bothered about it all being original and theft is not really a problem on american cars over here but i just did not want the messy looking wiring that some one had installed.I will not be able to try car for a while as it is dismantled at moment,i would post some pics but this computer crashed and i lost them all but you can check my car out here,
1989 Pontiac Trans Am - James's Pontiac

 

I found the resistor that has been fitted into the wiring but still not sure which key to buy.The resistor is showing 841 on my meter,so after looking up vats key codes on this site i am not sure if it is key 3 or 4.
Key 3 has minimum 650,max 728 and key 4 has min 850, max 942, do i go for closest value.

 

VATS System

 

Thats what i looked at but do i get the key with the closest match going up higher or do i get next lowest,key 4 has 850min,or key 3 which has 728 max,as mine is showing 841.