NEW Sound on fire wall on exterior Driver side

[mattinmt]

Today when I start up my 2000 Alpine I noticed a new sound. Once I arrived to the camp ground I put out the gen slide and noticed a motor running under the hood. The motor has rubber lines running from it to a round plastic cylinder. Can anyone tell me what this is and what it controls? How can I shout it down? Where can I get a new one? Any help would be great.

Thanks,
Matt

[mfire1339]

Matt. It sounds like a vacuum motor, possibly for your dash a/c system.

Mike

[dgerstel]

Matt,

That sounds like the vacuum pump for the dash heating and cooling system. It should turn off when the ignition or the dash system is turned off.

[mattinmt]

It turns off when I shout off engine. but still runs if I shout off a/c and heat. Does it always run. I don't remember hearing it before. Thanks

[Tom and Patty]

It is the vacuum motor for the dash HVAC. Mine makes and old electric razor type of noise. I use it as the "You left the key in accessory position again" alarm. The pump supplies vacuum to the HVAC doors ....defrost, dash, and floor. Mine will cycle on and off as the vacuum diaphrams lose vacuum.

IMO as long as it doesn't run constantly and the HVAC works at all settings (defrost, dash vent, bi-level, floor) properly, it is OK

[mattinmt]

I just read that the motor will run at higher altitudes. Make sense I am in Colorado and it just started acting up. I will check the lines to make sure there are no cracks.

Matt

[Retiredfields]

The higher the altitude, the more the pump runs. Above 7,000 feet, my pump runs non stop. The air pressure is too low for it to generate enough vacuum to shut off.

However, mine does not run when the AC/Heater main switch is in the off position....

[D & D Rich]

Matt,
Take a look at this IRV2 Alpine Thread, especially the #2 post by Gary Arnold. It worked for Gary and also Scott. However, it took a lot longer to take effect on Scott's. Here is the link: Click on the Red Link AC Vacuum pump failure - where do I buy one? It's on page 3 under (Vacuum Pump Failure)

Note: Your Vac Pump is not the same as Scott's, so don't go buy one like his pump. I recall there have been other posts about vac pumps, do a search.

The hose on the vac pump tank also falls off or leaks. You can fix by cutting a little off the end, put a wire heat shrink over the fitting, also clamp etc. You may also have too inspect the inside under the dash to make sure a hose hasn't cracked or fallen off. Or a bad valve. Any Vacuum leak will make the pump run all the time.

Dan R.
2004 40FDTS

[RKL]

High probability that you have a leaking vacuum line at where the line from the round ball attaches to the valve assembly that turns the coolant flow on or off to the heater core or where it opens or closes the heater core damper...Easy to check....just disconnect the vacuum hose from those two places one at a time and put your finger over the hose...If the vacuum motor shuts off with the engine running you have found the problem....If it doesn't shut off, remove a vacuum line from the ball and plug the nipple on the ball...if the motor doesn't shuts off, it is a leaky ball.....The first area I pointed out is a common problem because SM Fridigerette uses a flimsly rubber tube to connect to the valve assembly....good luck RKL

[takepride]

Quit yelling at your Alpine!

Oops. Sorry.

[dgerstel]

Matt,

Your problem is probably the altitude. There is a pressure (vacuum) switch in the pump that shuts off the motor at a set vacuum. While in Lake Tahoe with this coach, I found that my vacuum pump would not shut off. My '02 did not do this at the same altitude. I checked for leaks and found none. As soon as we drove out of the mountains the pump worked normally and would shut off when proper vacuum was reached.

[Rick J Fisher]

Read the thread "Noise in Upper Front End of Gen Slide" for a full discussion on vacuum leaks. My leaks were all at the controller. The ball is the vacuum accumulator. I found that bypassing the ball made the pump run for shorter bursts when vacuum was needed. Also try this link http://www.irv2.com/forums/search.php?searchid=497848

[Richard and Cris]

I had that problen last year. It was a vacuum line located under the dash. I think it was a black rubber line which linked to a three way "Y" connector. I was not attached well from factory. I reattached and glued and it has been right ever since.