Weird Buzzing Noise..????

pameridan04 · 03-27-2010, 08:38 PM

Hi guys:

Well I picked up my motorhome after getting a Laundry list of things fixed at the dealership. I drive away and 5 miles down the road I hear this wierd buzzing noise coming from the dash that I never heard before. I know that after driving this thing about 500 miles so far that I NEVER heard this BUZZ before.

I pulled over in a big parking lot and popped the front hood over the generator. The noise was coming from the hookup where the vacuum hoses connect behind the generator. I drove back to the dealership and they were at a loss as to why this thing was buzzing like that.

Now it just so happens that there was an exact 04 Meridan like mine on his lot. We went over and when you turned the key it buzzed the same way mine does. Don't mistake this buzzing noise with the buzz when you first start your DP coach that stops after 5 seconds. This stays on even after the caoch is running.

Well when I asked what does that vacuum setup do, they said it was for the heater and air conditioning controls, that they work on a vacuum because it is a DP. They said the noise was normal, which it wasn't because I never heard it before.

They were closing so I left. On the way home for the heck of it I put my cab dash heater unit fan on low, thermostat set to cool and floor and POOF no more buzzing???

So it buzzes like crazy when I have all my controls on the heater and AC set to off? What am I missing here.

Regards Jim P.

F&D ABQ · 03-27-2010, 09:04 PM

Quote:

Originally Posted by pameridan04

Hi guys:

Well I picked up my motorhome after getting a Laundry list of things fixed at the dealership. I drive away and 5 miles down the road I hear this wierd buzzing noise coming from the dash that I never heard before. I know that after driving this thing about 500 miles so far that I NEVER heard this BUZZ before.

I pulled over in a big parking lot and popped the front hood over the generator. The noise was coming from the hookup where the vacuum hoses connect behind the generator. I drove back to the dealership and they were at a loss as to why this thing was buzzing like that.

Now it just so happens that there was an exact 04 Meridan like mine on his lot. We went over and when you turned the key it buzzed the same way mine does. Don't mistake this buzzing noise with the buzz when you first start your DP coach that stops after 5 seconds. This stays on even after the caoch is running.

Well when I asked what does that vacuum setup do, they said it was for the heater and air conditioning controls, that they work on a vacuum because it is a DP. They said the noise was normal, which it wasn't because I never heard it before.

They were closing so I left. On the way home for the heck of it I put my cab dash heater unit fan on low, thermostat set to cool and floor and POOF no more buzzing???

So it buzzes like crazy when I have all my controls on the heater and AC set to off? What am I missing here.

Regards Jim P.

Don't know about Meridian, but my Alpine has a vacuum pump in front of the dash that is quite noisy and runs frequently (I probably have an air leak somewhere but am too lazy to run it down). My heater/dash AC valves and doors need vacuum to operate, and the diesel doesn't produce vacuum - hence the pump.

cbeierl · 03-27-2010, 09:27 PM

Sounds like you have a vacuum leak--it's probably a very easy fix. Here are a couple of earlier threads with pics, etc. for the problem: Vacuum Pump Failure and vacuum line leak anyone?

smlranger · 03-28-2010, 05:37 AM

Yepper....you probably have the famous leaking vacuum tube where it connects to the valve that opens/closes the damper in your dash heater.

Look on the passenger side of the coach under the hood. Near the HVAC box you should see a small can-like device with a vacuum tube on the bottom and little lever coming out of the top. The connector on the bottom splits and gives a small leak causing the vacuum pump to run continuously. Simple fix.

pameridan04 · 03-28-2010, 01:28 PM

HI Guys:

Thanks for the info, I will check out that green hose at the end.

Regards.. Jim P.

pameridan04 · 03-31-2010, 02:17 PM

Hi guys:

Damn you guys are GOOD. Stopped over where I store the motor home today to check out your suggestions.

Yep, the hose is cracked and split on both ends at the end of the elbow of the green vacuum hose. It wasn't even hooked up to the small canister.

Cost me all of .75 cents at AA store for piece of winshield washer hose.

That's why this forum is so GREAT... the information is invaluable. My dealer was at a complete loss.

Many Thanks again ... Jim P.