How are those aftermarket alarms hook up to the stock OEM alarm ? Which remote do you use ? Does the OEM alarm has to be disabled ? Does your progressive lock still work?

 

How are those aftermarket alarms hook up to the stock OEM alarm ?

An after market alarm will most likely "replace" the stock alarm. You will end up using the remote of the aftermarket alarm.


Does your progressive lock still work?
Depending on the alarm, most installers should be able to retain this function.

If you're going to get a remote starter in addition, you'll need to supply a "donor" key so the chip can be used to start your car.

 

The way my Clifford is hooked up I use the Clifford remote only.
When the Clifford is put in the valet mode like when at the car dealership for service. The Factory OEM alarm is working if the door is locked by key. When you open the door with key the OEM alarm is turned off. So with the Clifford alarm operating the red light on the drivers door never works but the Clifford has its own LED light. So the OEM alarm is never armed unless I would lock the door by turning key in lock. The Clifford alarm I have set to autolock & arm itself 90 seconds after the door/trunk is shut.

 

I also have a Clifford and my installer tied the factory system into the Clifford. I only use the Clifford remote but when I arm the car the light on the driver's door flashes like it always did (the aftermarket Clifford light also flashes). They did this so the OEM immobilizer system still functions correctly (need the key with the chip to start the car). Of course, the Clifford has a redundant starter bypass for immobilization purposes.