I have a 99 1500 ram 4x4 with the 5.9 that I purchased 2 weeks ago. It has a factory alarm and was wondering if it cuts off the fuel pump or ignition. So far it has failed to start twice. The first time I opened the passenger door with the key (I don't have the remotes) and the horn started beeping. That was when I realized it had an alarm. I put the key in and tried to start it. It would turn over but not crank. After unlocking the driver door with the key the alarm stopped. I did not try to start it then, but 10 minutes later it started fine.

The second time happened today. The truck has sat for about 5 days. I opened the driver door with the key. The horn never sounded, but about 5 minutes later I tried to start it. It turned over fine and would stumble a few times but would never start. A slight bit of smoke was coming from the exhaust. A couple of hours later I unlocked the driver door, started it, and it ran fine.

So, is the alarm connected to the fuel pump or ignition and things happend as they should or is this a coincidence and I have another problem?

Sounds like there may be some issues with the alarm, so I'd address that first then see if the problem continues.

I did find out that the alarm sends a no-run signal to the PCM but this was not the problem.

After realizing it just rained when I had the starting problem, I read on another post that the distributor cap and rotor might be the culprit. After changing them (I did the plugs and wires too) it starts fine, even after a heavy rain. The old cap and rotor looked very worn so quite sure that that was the problem.

Ha...the old "water in the distributor" problem. Good catch, easy fix.