Chieftain startup beep

is it a seatbelt warning beep, or is the step not retracted?

we get warned about both these 'events'....

No not any of those and besides that wouldn't account for it not sounding for miles and then sounding. It starts with a slow beep that becomes quicker and then stays as a constant noise. It then drops to a beeping and then goes off.

fridge door open?

Handbrake not fully down?

Agree with TW, check the handbrake micro s/w is secure and set in correct position.....

The noise comes from the front speaker so I think that would rule the fridge out wouldn't it?

A long shot this ,but , has the Vechicle got reversing sensors? and some how although you are  not in reverse the system is faulty and they are picking up the cars behind you 

The noise comes from the front speaker so I think that would rule the fridge out wouldn't it?

No not any of those and besides that wouldn't account for it not sounding for miles and then sounding. It starts with a slow beep that becomes quicker and then stays as a constant noise. It then drops to a beeping and then goes off.

interesting, you didnt mention the sound was coming from the front speaker nor did you describe the way the noise was manifest, yet, when i offered possible solutions, you ruled them out, quoting both these 'obvious' things back at me as if i should have already known them.....

perhaps of you had given a bit more info as to the nature of the sound and its source, i wouldnt have come back with such obviously wrong suggestions.....

good luck with resolving the issue....

That rather changes the scenario, Soreinsky. If it comes out of the speaker that gives you a huge clue. 

I am not ruling out anything you say and I am sorry that I didn't explain fully but this is because I didn't envisag the answers. I will explore all the answers I receive today more fully tomorrow when I take the MH out to test the theorys the kind contributers have put forward.