Might not be the right area to post, but..

[Blueox]

My son now reports a strange buzzing sound when the cruise is on and he goes up a hill under acceleration. Only when the cruise tries to accelerate to maintain speed. It seems to be located under the dash or somewhere forward. If the cruise is off and he has to accelerate to go up a hill, it doesn't happen. Happens only with the cruise on.

Anyone know what might be going on?

 

[RonD]

There is a "vacuum dump valve" that could be making the noise under the dash.
It releases vacuum at cruise control module when brake pedal is used, it is a fail safe type device, and the only thing I can think of that would make a noise.

This is a diagram for that part of the cruise control:
http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Cruisecontrol_1of2.JPG

 

[Blueox]

Thanks for your response.

Well it happens only with cruise on under acceleration. So that may not be it.

 

[RonD]

Only time that dump valve would have a vacuum is when cruise control was on.

And vacuum pressure changes as you open the throttle.

 

[Blueox]

Sounds good to me.

This kid has such good hearing, I think he can hear like most dogs. I can't hear as thing.

 

[RonD]

I would find the vacuum hose that goes to the "dump vale" on the cruise control module in the engine bay.
Then pull that hose off the module and suck on it, if dump valve is good it should hold a vacuum, if you have to keep sucking on it then valve or hose has a leak.

 

[Earl43P]

Mine buzzes too if I don't rest my foot on the go pedal (so I do that, and always have). Seems to be worse when it's cold out.

Never really looked into fixing it. Shrug.

 

[Blueox]

Well it is dam cold in Minnesota. I will suggest he tests it.