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Robbie_Welch's avatar
Robbie_Welch
Explorer
Nov 04, 2019

1999 Monaco Windsor Dash air/heat trouble

My 99 Windsor only blows thru the defrost vents. I know this is the default function because of no vacuum. My question is where does it get its vacuum from? I though there would be a 12volt vacuum pump somewhere but haven't found it. I did find a solenoid in the vacuum system but no pump. Any help with the vacuum source location would be greatly appreciated. Robbie
  • That was good. So many things on these motor homes are simple to fix if only we could find what is causing the problem---
  • Thanks Oldave I reconnected everything fired up the coach and it worked perfectly. The electrical connection was the problem. Thanks again
  • Robbie Welch wrote:
    Oldave rereading your reply the vacuum generator may be what I was looking at. I did find a bad connection on it but I never fired up the coach after nothing ran after I repaired the connection. I'll put it back together and run the coach to see if its repaired. I'll let you know how it goes. Thanks


    Right Robbie you'll need to run the engine because the vacuum gen
    uses air pressure .
    Finding the bad connection will probably fix your problem .
    Good going .

    Ray
  • Oldave rereading your reply the vacuum generator may be what I was looking at. I did find a bad connection on it but I never fired up the coach after nothing ran after I repaired the connection. I'll put it back together and run the coach to see if its repaired. I'll let you know how it goes. Thanks
  • Its a diesel.I found that small back box above the generator that appeared to be a solenoid to me. It had a switch and a small cylindrical shaped unit that a think is a solenoid. I say that because I took the electrically connected part off and didn't see any type of diaphragm or pumping parts. The pump/solenoid had a air line and a vacuum line attached to it?
  • Robbie ,
    Mine has a little black plastic 12v pump above the gen .
    On some coaches mostly earlier models they used a vacuum generator
    powered by compressed air blowing over a venturi .
    I believe it is a metal box with an air and vacuum hose attached .
    Should be mounted on the firewall above the Onan gen .
    They are very reliable as there is not much to go bad , maybe the
    elect air valve or stopped up inside . Cleaning should take care of that .
  • Is your Monaco a Diesel? Diesels use a vacuum pump whether mechanical (belt driven) or electric. Gasoline engines provide vacuum so there are no pumps.