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Topic: Dash controls (Read 449 times) previous topic - next topic

Dash controls

So I got my ac cold and working. Thanks for all your help in this. Now I can't seem to get the controls to change from dash to floor.
I'm wondering if the vacuum thing in the step well has something to do with it. I'm not sure how this works or it even works. It is  leaking air.
The following photos the parts and does any on know what it controls and how it works.
Thanks again

Re: Dash controls

Reply #2 –
Ok so it's an obsolete vacuum generator. Does any one know how it works and what it operates?
I would like to possibly fix it. I do notice that air is coming in from the large hose that comes into the step well and I'm assuming that the air goes through the generator and vacuum goes back through the small line to the dash?

Re: Dash controls

Reply #4 –
A couple years difference in our coaches, so I'm not sure the system was the same in '99...but mine was made by SGM - there was a sticker in the dash of mine.  They furnished me a diagram.  If yours is the same, here it is.  If not, and it is a SGM provided system, contact them - I bet they have the schematic for yours too.

https://sgmcoinc.com/

Re: Dash controls

Reply #5 –
Quote from: Gold Nugget finder –
I'm wondering if the vacuum thing in the step well has something to do with it.
Most likely yes, that is your vacuum source to control the dash/floor actuators in the dash area.

You can see the two actuators (driver and passenger) when you lift up the center console.  If you want to test them you can detach the line leading to one and give it the old straw suck, it will take very little vacuum to open them up.

Here are some details for the 2000 model

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If those actuators work, and you are getting 12V down to the black box in the step well (and you have pressure in your air tanks) , then that is most likely your problem.  My understanding is that when the system opens the solenoid, it expels air,  which causes a venture effect on that plastic check valve, which allows vacuum to build up in the coffee can canister.  Its told to turn on/off by that vacuum relay (in your picture 4)

The most common issues are:
1) The one way check valve as failed, replace it or clean it (in your picture it appears to be the yellow plastic part, in the picture I've attached its the blue one) You should be able to blow air through it in one direction only.
2) The coffee can vacuum reservoir has developed a leak(s), patch it with some JB Weld
3) The vacuum on/off sensor has failed and never tells the solenoid to open, replace it

On mine, the air hoses are quick connects, just push/pull the collar and slide the hose out, easier to work on this when its on the bench.

Re: Dash controls

Reply #6 –
Quote from: Gold Nugget finder –
Ok so it's an obsolete vacuum generator. Does any one know how it works and what it operates?
I would like to possibly fix it. I do notice that air is coming in from the large hose that comes into the step well and I'm assuming that the air goes through the generator and vacuum goes back through the small line to the dash?
Did you read the text? I repaired mine with the information I provided. The large hose has air pressure from the coach when the ignition is turned on. It makes vacuum by venturi effect and goes to the reserve can which then goes to the dash controls. If the check valve fails you don't get vacuum. You can also buy 12 volt vacuum pumps listed in the links on the forum.
 

Re: Dash controls

Reply #7 –
Thanks for all your help.
I've ordered the new system and plan on replacing the old stuff.