Cadillac Repair: 1990 cac, ohm meter, interrogator


Question
QUESTION: can you tell me how to by pass the alarm  sys ? please!

ANSWER: Hello,

If you are referring to the wonderful flashing lights and horn in which owners felt so good about the factory including it, you now have a problem.

Replacement parts have not been made for 15 years.

Bypassing it is next to impossible, not because it was secure, but because it is tied into so many circuits.

If it is bypassed, you may lose your headlights, maybe your stereo and who knows what other options.

The absolute worse option on all cars is a factory alarm that was obsolete when the car is sold new. A major ripoff from the manufactuer as it still is, and yet people buy cars with this ineffective system that is doomed to fail.

I have worked on factory alarms since 1986. In fact, when the dealers couldn't fix them they came to us.

As I said though, bypassing you are going to lose things.

At least with after market alarms failing, you could rip them out and be done with it.

You did not say why you wanted to bypass the factory alarm.

Could you tell me what problem you are having?

---------- FOLLOW-UP ----------

QUESTION: I was talking about the security system that stops the you from starting the car, we have changed the switch but the code will not re-set and car will not start.  that is what we want to by-pass  thanks

Answer
Hello,

I thought you might mean the VATS, but these came with alarms too and that is why I asked what your problem was.

Now, just changing the lock will not get the car running, which means it needs to be coded to the proper resistor chip before you can bypass it.

I really wish people did not mess with this stuff without studying exactly what they were doing first.

I hope you still have the old key for the car.

If not, it is going to get very costly for you.

The resistance of the old key needs to be read with an ohm meter.

If you don't have the key, you need to call a locksmith to read the system with a tool known as an interrogator. I know of locksmiths charging up to $300 to do it.

There are 15 different resistors for this car.

Once the resistance value is derermined, only then can the vats be bypassed.

The cheapest easiest way is not to screw with it yourself and have the local alarm store bypass it.

They get the vats bypass kit with every alarm with remote start.

Have them do the bypass, shouldn't  cost much.

At the same time have them install a hidden starter kill switch. Not under the dash, but hidden!


Old cars are stolen all the time. You need to do this.

The steering column can be defeated in seconds on the left side of the column with a screwdriver with no damage to the ignition lock.

Another great GM idea!

I have rebuilt thousands of these columns from theft.