If the doors were lock and the alarm system armed before the battery went dead the system will be armed when the new battery is connected but may not sound. Unlock the vehicle with the remote or key (even if the vehicle is already unlocked). Turn the key to the run position and look at the instrument cluster for an indication there is a security system problem.
And if it is a security problem, how do I fix that
I looked at the instrument cluster and no indication of a security problem. I hear the fuel pump when I crank it. The humming sound. I gave it a jump also if it needed more juice but nothing worked. Could it be the alternator?
may sound like a stupid question, but are you sure it has enough gas. If you are unsure you could add 2 gallons and try it again. You may have a leaky tank and the little that was in there before it was parked drained low enough that now it doesn’t reach the pump. A very slow drip…over a month of being parked…could empty it.
I wouldn’t trust the gauge, I’d just add two gallons and that question will be eliminated.
Yosemite