Aftermarket alarm and factory warranty?

[RAM H2 RYDER]

I have a black 05 H2 and it has a dvd system with 4 monitors and I took the advice of members here and others and got an aftermarket alarm installed. I got a viper alarm with 2-way pager and remote start, my question is does this now void my warranty? I ask this because my installer told me that sometimes it does and that seems insane to me but I figured I would ask you guys about it. He also said adding an aftermarket stereo would do the same. Sorry if this has been asked in the past but I did a search for and could not find what I was looking for.