91 Alarm

I have a 91 coupe, and would like to install an aftermarket remote entry, alarm, and starter system. I don't really care about the remote starter functionality, just the alarm and remote entry. My question
is, would there be any problems with the original security system if I use one of these aftermarket units? This is my first vette, and I must say I'm having a blast, but I really miss having remote entry.
Dean
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on 10/3/2005 2:35 PM DeanW said the following:

Speaking to GM Products generally I would say that with a COMPETENT installer you should have no problems. You will no longer be using the proxity fob, if that's what you now have (as I do on my '94) but a good alarm system and installer will replicate the resistance in the key (again, assuming you have that) or the VATS key in newer models.
You use one alarm system or the other - not both.
I left the '94 alone but did switch over to an aftermarket alarm/starter on my Park Avenue where I DID want the remote start.
Look for stand alone installer rather than messing with Circuit City/Best Buy, etc. Look for one that's been around for awhile or is recommended to you by a satisfied customer. Ask how they hook it up and if they don't tell you that they solder all the connections, walk away - FAST.
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A 91 has a Vats System that protects your car. It kills your emissions. You can have an alarm installed with a remote that will open your car and operate the alarm. I would suggest that you forget the remote start function. To use that function, the installer will have to sub the resister (that's in your key) somewhere else in the car so you can start your car remotely. this is not a good idea to make the Vats usable at all times.
g'luck
--
"Key"



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I have the same question, but no answers.
What about the factory alarm? If you splice an aftermarket keyless entry system into the OEM power door locks, it will arm the factory alarm when you lock the doors with the fob. When you unlock with the fob, through the power door lock circuit, and open the door, the original alarm will go off.
It would be doing exactly what is was designed to do. Is there a way to permanently disable the OEM alarm?
As for the remote starter, mine's a 6-speed. I can imagine bumping the remote in my pocket and seeing the car erupt through the garage door and drive off.
There are aftermarket PROMs that will disable the VATS. A friend of mine used one to swap an LT1 into a Jeep. No resistor key.
-rev
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on 10/3/2005 4:46 PM The Reverend Natural Light said the following:

Perhaps, that's why I conditioned my answer on GM products in general rather than Corvette specific. In the two Buicks which have had aftermarket alarms/starters installed, this was never a problem. The alarms I had were made by Audiovox and worked quite well.
In the new Buick they didn't completely disconnect the factory alarm ergo I had to train myself NOT to manually lock the doors (which sets the factory alarm) but to just let the aftermarket alarm "passively lock" the doors and set the alarm 40 seconds after the last door closes. If I do hit the lock button getting out of the car, the aftermarket alarm still functions properly but when I unlock it using its remote it does nothing for the factory alarm and pandemonium reigns supreme until I use the key to unlock the door.
The various alarm manufacturer's provide their dealers, etc. with somewhat complete instructions for retrofitting their aftermarket product in vehicles with factory alarms.

Don't think that can happen. You can't start the engine on your 6-speed unless the clutch is depressed or the transmission is in neutral, can you? Takes more than a bump on most remotes as well. Both of mine required two sustained presses on a button within two seconds of each other. Still, it could happen. The higher end alarm I have now is also a receiver and will alert me when the car starts, when it shuts down, when the pre-alarm or alarm sounds along with a graphic display on the LCD indicating the reason for the alert.

It allows the alarm to "fool" the VATS or whichever system your GM uses but, as I understand it, does NOT disable that security measure. When you use the remote start it puts the key (my newer one actually needed a working key rather than just a matching resistor)into the circuit. If they had just the key - without the resistor or VATS, etc. - and tried to start the car, it would not work.
The options available on these newer alarms are nothing short of amazing but bear in mind that the "cuter" or more complex you get, the greater the chance of something going FUBAR.
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If would if the remote start was wired to the starter solenoid. For a manual transmission, I'd want some kind of safety interlock between the remote start and the transmission, so it would only work in neutral.

My brother worked the parts counter at an Acura dealership. One of their techs hit a key fob button "to see what it did" and ran an NSX through the shop wall.

There are devices available to fool the computer into seeing the VATS key resistor, but the new PROM completely disables the VATS system. The wiring harness we used for the LT1 didn't even have the VATS wiring so the new PROM was required.
-rev
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I have a 91 coupe with the regual VATS system and I had a viper alarm installed by a certified DEI technician at Tweeter. It works just great. I have remote entry, remote start (which is nice on the hot days if I remember to leave the AC on) and most importantly (to me) rear hatch remote. The technician at Tweeter solders all of the connections and let me try to explain how he got the remote start working. He installed a relay with a suitable resistor for the remote start. When using the remote start, that resister serves the purpose of activating or deactivating the VATS. If i use the key to normally start the car, then the resistor in the key works. When using the remote start, it will run for 12 minutes and then shut off. it does not unlock or disarm the alarm in remote start. when you go to get into the car, you have to unlock the doors with the alarm and put the key in the ignition and just turn it on. if you step on the brake before you do that, then the autokill kicks in and the engine dies. if you do that, you simply put the key in and start it normally.
the technician that installed mine has installed viper systems in all makes of cars including several corvettes (C2 through C5) as well as complete sound systems, navigation systems and the like. he has been installing systems in cars for about 6 years and received his training at a place in canada (toronto i believe). Can't remember the name of the place but I know he got the training as I paid for it. the technician is my son so I trust his work.
mike

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thanks for the details. I learn something everyday that I am lucky enough to wake up :-)
g'day
--
"Key"
(the locksmith that don't know squat about alarms)
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'Key wrote:

Agree those days are great. Sometimes I learn two things--those days are overpowering! PJ
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oh shit... can't handle many in a row.. my heart will not allow anything "overpowering" :-)
g'day
--
"Key"



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Thanks for the replies. I guess I have 2 issues to work around, the VATS and the alarm.
So, another question - if I lock the doors via the remote control, will that set the factory alarm? If so, can the line to the door lock switch be either opened or closed as neccesary to prevent the alarm ever being set.
The VATS I understand can be dealt with via a resister, using a relay tied to to the new alarm to swap the resister into and out of the ignition lock cylinder VATS circuit.
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