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rmcobb · 08-23-2021, 07:28 AM

So, about an hour from our destination I started hearing a noise coming from within our dash. Vibration, motor running type of sound. When arrived at CG, I lifted the hood and diagnosed it was coming from the indicated device. Was vibrating and running continuously. Appears to be part of the dash A/C system maybe??

I disconnected the wires going to it and it quit. Went back in and tested the Dash A/C and vent fan/systems and all seemed to be working OK.

Can anyone tell me what this is, and what it does (some sort of vacuum pump or something?)

Thanks
Randy

TonyMac · 08-23-2021, 07:36 AM

It's a vacuum pump. It creates vacuum to run your dash HVAC controls.

Algoma · 08-23-2021, 07:41 AM

Yes it's the vacuum pump that operates the A/C vent controls. Usually when it runs continuously it means a hose has fallen off.

TonyMac · 08-23-2021, 07:41 AM

Above it you see a half sphere. That is the vacuum reservoir. It stores vacuum for use when you reposition the dash hvac vents.

The big green thing underneath is the generator (duh). The plug on the left side of the generator goes to your dash generator controls.

The white sticker with the "2.5" on it: Just under it is the fresh air intake for your dasah hvac

rmcobb · 08-23-2021, 08:06 AM

Quote:

Originally Posted by TonyMac

It's a vacuum pump. It creates vacuum to run your dash HVAC controls.

OK, kind of what I thought. But why when I disconnected it, did the dash A/C still seem to work OK, or maybe I just didn't let it run long enough.

Quote:

Originally Posted by Algoma

Yes it's the vacuum pump that operates the A/C vent controls. Usually when it runs continuously it means a hose has fallen off.

All hoses are connected. That doesn't seem to be the reason it is running continuously.

When the unit goes bad, could it result in this condition?

Algoma · 08-23-2021, 08:57 AM

Have you checked the dashboard selector switch. I haven't checked on mine but usually the vacuum line goes to that switch and then gets routed from there to the relevant flaps. If you look at the small blue hose, it goes to the A/C vent above the generator. This vent flap should open when the selector is in VENT but close when you select A/C. If it doesn't, I would suspect the selector.

This website some info that might help https://www.proairllc.com/design-eng...empcon-guides/