93 mazda 929, bulldog 62I

Not the siren ground, the ground for the alarm brain itself.When the alarm brain's connection to ground goes bad, it will try to pull ground through other connections, such as the domelight, horn, or ignition wires......with limited success.So generally, if the alarm is otherwise installed correctly, but the brain isn't grounded, it'll still often work well enough to lock/unlock the doors, but with very weak siren sound, as you describe.

I would recommend re-locating your siren. I always install them so that the "horn" is pointing down, that way no water can get inside of it and pool up.

How do you get the headlights to flash with the parking lights when the alarm is going off?

when adding a second siren can you just tap into the siren wire from the first siren?

why is the starter wire on the ignition harness reading negative zero in all postions except when cranking it reads about 3.4 volts I never show it jump to 12 volts what happen?