Re: septic pumps
The alarm is just a float in the septic tank. Not the float that operates the pump, but a seperate "alarm float". The float is just a dry contact closure (well, sometimes mercury wetted) that closes two terminals at the alarm box. The alarm box may not have power for some reason, or the float may not be adjusted properly, or the float or associated wiring may be bad. The alarm box is sometimes a buzzer in the house, or sometimes an outdoor enclosure with a buzzer and a red light.
I'd first jumper the float terminals at the alarm box to rule figure out whether the box is working or not. If the alarm sounds, then the trouble is with the alarm float or the associated wiring. This often necessarily involves having the tank pumped out for further troubleshooting.