Car Alarms: bad alarm?, volts and amps, clock radio

Question
My 97 silverado has an aftermarket alarm installed not sure who made it or installed it. Problem is the truck will not start at times, the battery will check good for volts and amps but no juice is going to the truck, even the clock radio will be dead but the dome lights are bright. I have no sound when turning the key and the fuel pump makes no noise. When I arm and disarm the alarm a couple of times it seems to reset something and the truck comes back to life. My clock will be reset but all the preset radio stations are still there.
Any help or ideas would be helpful  

Answer
Does not sound like an alarm glitch, ergo the radio. Different system and power sources. I would hazard to guess it's an alternator issue since it is showing an intermitancy accross a wide range of electronics.
Unlikely to be the alarm though. Your Gremlin, if
traced back to the battery and it is fine, would be in the power distribution center. But you need to get in there an trouble shoot when the trouble arises. Can take some time.
Once sure way to determine if the alarm is at fault is to disable it. then if still having these issues, keep looking. If it is the alarm, the replace it with one you know from the start to make it a better experience.

Good hunting.

ALARMTEK