We just got a motorhome on the 1999 E450 V10 chassis and I am having to work out a few problems. There are some vacuum lines that have been chewed thru and I need to fix them. I found a RED 1/8" line near the battery tray that I dont know where it goes. I removed the battery tray and the blower fan and still nothing. Vacuum diagrams would be great. Thanks.

 

I've moved your thread to the 1968 - 2013 Full Size Van forum. Hopefully you'll get better response here.

 

Are there any devices or features not working? Air flow thru the duct work for example?

Does the line appear to be a factory item or something the MH builder added?