By: Frank Lanier
I replaced the battery in my Larson boat, and now, when the key is on, I always hear a low continuous whistle from the side of the Fireboy while its indicator light is green (charged). What do you think it might be?
First, I have to assume you’re talking about one of the various Fireboy Xintex Discharge alarms, such as model DA-1001-011 (a common dash-mounted model). If the problem started after switching out the battery, there are only two scenarios I can think of that may link the two. One is that the battery polarity was somehow inadvertently reversed during the installation, which could have damaged the discharge alarm system. A more likely possibility involves the yellow sensor wire that runs from the fire extinguisher pressure switch to the discharge alarm unit. This sensor wire is normally grounded; however, if the extinguisher is discharged, the pressure switch opens the circuit, removing the ground and causing the discharge alarm unit’s horn to sound (which is the same way the “press to test” switch works). If the connections for this wire were knocked loose or the wire itself was damaged during battery installation, it could cause the problem you’re describing.
If the wiring and connections are good and the extinguisher is fully charged, yet the horn still sounds, then the system should definitely be inspected and repaired by an authorized service technician.