Brand new perfect pass install

[CJD]

With the engine running the alternator will bring the voltage up some, although 9.5 is a large drop. With the key on and engine off, what are you showing for voltage across the battery terminals? If it also drops there, then the battery charge is low. If your drop across the battery is still 12.4 or so, but the power to the PP is 9.5, then your wiring is not sufficient to handle the loads you have. Also corrosion could cause a large voltage drop across the ignition switch. You can trace the voltage loss by testing voltage ahead and behind each switch and connector until you find the restrictive wire, switch, or connector.

Remember that a perceived voltage drop could also be a bad ground, bringing the negative side up.

The beep usually doesn't happen unless you are running and moving. Mine does not beep just sitting with the engine not running.