Dash A/C vacuum Leak?

[wlf00]

Normally, when I start the motorhome, I can hear the vacuum pump run for a few seconds and then stop. Recently, I found that the vacuum pump was running all the time (or almost all of the time).

I was doing some testing today and found out that it seems to work OK when the mode selection switch is in all but two positions, Off and Max A/C. If I move it to one of these two, the pump starts and runs continuously. When I move to any of the other positions, it stops after a short period of time. When I move it back to one of those two positions, it starts running again.

I suspect that this is not normal. Does anyone have any suggestions on where to start looking?

Thanks for any help you may have.

[tomsm]

Bill - look behind the front "hood" for the heater control valve. It's a small valve with 4 water hoses attached. There is also a green vacuum line connected to it that actuates the valve. You will probably find a split tube that's causing your leak. Here's a link to a previous thread with good pictures...

[wlf00]

Tom,

Thanks you for your post. I went out this morning to check and that is exactly what it was. The short tube had a split in it. I removed the tube along with the small elbow, and connected the remaining tube directly to the value as mentioned in the post you had a link to. It now works like a charm.

Thanks again,