Noise in upper front end of gen slide

[Alpine Road Warrior]

I was getting ready to leave Verde Valley TT and as I walked by the front end of the coach I heard a noise like a motor running. It is a small pump of some kind that has something to do with the dash A/C unit. It only runs when dash A/C unit is on. The pump is hanging by the wires hooked to it. I do not see where it is to be mounted. The A/C works fine but I don't think it is very good hanging by it's wires. Anyone know the purpose of this pump and where it is to be mounted?

[EngineerMike]

Sounds like the vacuum pump that has a plastic ball about 4" diameter attached; the ball is the vacuum tank. Vacuum is used to power the switch that changes the AC/heater settings. Mine is mounted to the firewall above the bottom lip of the top cap and over close to the D.S. fuel fill.

[Alpine Road Warrior]

Thanks Mike I will see if I can bend my neck that far and get it back in place.

[dgerstel]

Make sure that the vacuum tube has not been damaged by the pump hanging on it. If there are any leaks in the tube, the pump will run all of the time the AC/heater/vent is on. When all is well with the system, no leaks, the pump shuts off after the proper vacuum is reached.

[Alpine Road Warrior]

Thanks Dale, I will check that out. It was running all the time the A/C was on.

[Rick J Fisher]

Check this thread for a discussion on vacuum pump system leaks.

2004 AC control panel problem

[dgerstel]

It the pump was hanging on the wires only, then it might have just pulled off of the tube.
Make sure that the rubber grommets/feet are not missing and don't over tighten the fasteners. It is mounted sort of like our water pumps. If the pump is mounted too solid, it will make a lot of noise.