When I purchase an upgrade card with an action on it (ex. Marksman), does it go onto my "action bar"?

I ask because there is a crit damage card (damaged sensor array) that states "you can not perform actions listed in your action bar".

We played it as; the upgrade action is NOT on your action bar, and you can therefore still do those actions if desired….

Thoughts?

No. Certain upgrades state "your action bar gains…" while others do not.

Agree with Grimwalker.  Sounds like you played it correctly.

Related to this: my 9 year old son (!) tried to game me the other day. On Squad Leader it says the chosen ship may "perform 1 free action." It says nothing about it being on the action bar or not. So he was trying to allow an unmodified TIE fighter to do boost! I had to explain to him that this was not allowed. You can only perform actions that your ship has access to. Otherwise you could give target locks to TIEs, or Barrel Rolls to Y-wings, or any number of goofy things that are not intended by the Squad Leader card. Nevertheless, he did expose a bit of a weakness in the wording of that particular card.