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.
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 -
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
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.
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.
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.
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
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
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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