2004 colorado remote start ok, alarm not

2004 Chevy Colorado with factory installed alarm. A remote starter (Avital model 4103) was installed and works; but the alarm will not work with the new remote starter remote.  I can still activate the alarm with the old remote though.  I don't want to have to carry around 2 separate remotes!  What needs to be done so I can arm/disarm the alarm with the new remote?MattC

Does the new avital remote lock and unlock the doors. If so, then it is most likely triggering the factory alarm to arm and disarm. But you wont hear that horn hork when arming with the avital remote. Try this to see if its working... Lock your truck with the avital remote but leave the window rolled down. Wait at least 3 minutes, then reach in thru the open window and unlock the door MANUALLY, dont hit the power unlock button. And then open the door. If its hooked up correctly, the alarm should go off and the horn will be honking.

Thank you for the suggestion!  Did what you suggested but the alarm was not set.  Does anyone know how the wires are supposed to be hooked up?  The alarm was initially bypassed to allow installation of the remote starter.  Did they not hook up something to allow the alarm to be set by the new remote? Thanks for any help with this!MattC

Now that I've looked, every wiring diagram I found says N/A for the factory arm and disarm wire color. Now this would mean one of two things. Either there isn't actually a factory alarm or else there no way to physicallt rigger it without the actual remote. Do that same test again but with the factory remote and see if it goes off when you open the door. If it does indeed set off the alarm, then you do have a factory alarm and are basically stuck carrying two remotes. The only other option would be to have the remote start triggered by the factory remote. Some reote starts have the ability to be triggered by a series of pulses(like locking the doors 3 times in a row with your factory keyless remote to start it).

Yes, it locks and unlocks the doors.MattC

Let me know how it turns out when you test it again with the factory remote.

The alarm goes off using the original factory remote.  So....Is there another remote starter with alarm that could be purchased/installed that would give me both (alarm &remote start)?  I would  not use factory alarm at all. Or would I run in to same problem.  Thanks for your help. (don't want to carry 2 remotes)MattC

Yeah you would just have to get an alarm/remote start combo unit. Not just a remote start unit with keyless entry.