siren not working

i installed a police siren in a volenter ems. truck hes also a officer. so its ok. the siren is a federal signal ms4000. it was working fine. the other day day we were using it going to a call and it was ok then made a funny noise and stopped working.so i checked it out checked the connections and it still poweres up. you used to hear the siren very low from the siren box itself when tunred on. now i dont here it anymore. can something have blown out in the blox, im guessing its like an amp. so is there something i should test and can repair myself.heres the manual and the specs of the circuit board is on the last page . please let me know sorry for the long post http://www.fedsig.com/products/docs/install/MS4000_Installation.pdf

no one has any ideas?

i do some instills and what i found what you are describing is a problem with the speak not the siren unit. The unit is working it just does not have a speaker. will start to look at the wires and if look fine change out the speaker. what model is the siren on some unit have two power lines if one don't work could have the low sound.

Sorry...not real familiar w/ those units...But in car alarm sirens...When you get a funny sound...Its normally the ground connection...M.E.C.P & First-Class

Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!

Check you power and ground connections first. Check their physical connections not just with a DMM. The manual states that an 11 ohm speaker be used with this unit. Was the recommended speaker used? From the way the manual is written, the sounding device is a speaker and not a siren, so try connecting a regular speaker to it. You can add a resistor inline bump the resistance up but don't operate the unit for more than a couple of seconds. You just want to make sure you can still get the unit to drive the speaker. If you can't get any sound, the amp/unit is probably dead. If you do get sound, either the speaker connection is bad or the speaker is bad. This is what I would do first.