I need help ... there is a loud whistle in my bus...

[orbitalsolutions]

I went into my bus this morning and there is a loud whistleing type
sound coming from the front otf the coach. sounds like an alarm.

I have no idea what this is. on the closet wall there is a tester
paned for propane, but it is not that. I turned off the 12 volt master
and the whistle remains.

Does anyone know what this might be, it's quite annoying, and I havn't
been able to locate the source of the sound yet.

Thanks.

--James