Resonate 29D Siren noise

[Birchsr]

When we start off on a trip, we will hear a siren noise that can last for several miles. There are no dash indicators flashing and no governors on engine. We called the dealer while the noise was going off and they could not figure it out. It is hard to duplicate this noise when at the dealers location. After a while it goes away but the siren noise is very loud and scary.
Help

[16ACE27]

Levelers system complaining the jacks aren't fully retracted?

When exactly does it start? When you put the gear lever in drive?
Does it only exist while moving? Or also when stopped?

[ghnl]

Does it make the noise on first start up (cold engine)? Idling? If you rev up the engine while idling does the noise change? Does it only make the noise while moving?

Got any pranksters in the family?

[Birchsr]

It will start when I have driven for 30-40 miles. It will shut off and may not start again for the rest of the trip?

[ghnl]

Just a guess - many engines have a clutch operated cooling fan. If so, it wouldn't likely be engaged (in other words the fan would be free-wheeling) until the engine warms up. So maybe the fan is making the noise when the fan clutch is engaged? Perhaps the shroud is too close or loose and the spinning fan is slightly contacting it?

[ghnl]

Does it sound like the one in this thread? If so, that isn't what I was imagining.

Perhaps these two threads could be merged? (if, indeed, the siren noise is the same)