You can test the alarm speaker at the dash by verifying it has a good 12 volt (+) supply, then remove the tan/blue wire and provide a good ground. The alarm should sound. If not, the alarm itself is bad and needs replaced. The alarm should sound momentarily at key on, engine not running to inform the operator the alarm is working.
On an efi engine the easiest way to check the alarm circuit is to key on the ignition, engine does not need to be running, and ground one side of the gear lube monitor wires (either wire that leads to the monitor not a wire from the monitor) and the alarm should sound
