1999 Cadillac Deville Air Ride

Discussion in 'Domestics' started by leon phelps, Mar 28, 2011.

  1. leon phelps

    leon phelps Newbie

    Joined:
    Feb 21, 2007
    Messages:
    10
    Likes Received:
    0
    Hello,

    The air ride is stuck up in the air on the rear.

    I have removed air pump above the muffler. When I hook 12V to the first and third connectors on the plug the pump runs fine.

    There are two pink/black wires that are #'s 2 and 4. I did not want to hook power to them. The #1 was black and #3 was black/green.

    When I removed the clip, the air went down and the car is now drivable.

    I am unsure what to try next. I saw the leveler on the drivers side near the axle. I disconnected it and tried to move it up and down. No change. Should I remove this next and check for changes in voltage or connectivity when the switch goes up and down?

    Also, where would the front pump be? This pump only had two connectors for the rear and a vacuum connection the looked to go above the tank to the charcoal canister.

    Any points in the right direction would be appreciated.
     
  2. Gus

    Gus wrench

    Joined:
    Dec 8, 2006
    Messages:
    2,389
    Likes Received:
    0
    Think this year only has air shocks in the rear.......

    Question is, is it the level sensor that is bad, or the vent solenoid that is bad.....the vent solenoid, I believe, is not replaceable, it's part of the compressor.....
     
  3. nickb2

    nickb2 Wrench. I help when I can

    Joined:
    Nov 22, 2008
    Messages:
    3,256
    Likes Received:
    8
    Gender:
    Male
    Occupation:
    Ex car tech
    Location:
    Québec, Canada
    Yup, exhaust solenoid comes internal to comp. Could be the CVRSS continuously variable road sensing suspension exhaust solenoid control . Best way to know would be to ground the white wire of the compressor connecter. Orange wire going into the compressor should be hot at all times, so grounding the vent of the compressor should deflate the suspension and rule out the vent. So if you have 12 going in on orange wire, and white wire is good from compressor to CVRSS module, the compressor needs replacement. Since motor runs in compressor, I assume the drk green wire is good and CVRSS module ground is good. Here is a diagram that explains the circuitry.

    [attachment deleted by server]
     
  4. NickD

    NickD wrench

    Joined:
    Aug 28, 2007
    Messages:
    4,299
    Likes Received:
    0
    [​IMG]

    Made Nick's circuit a bit easier to read so you don't have to twist your head. Your problem reminds me of my 78 Fleetwood with level control, only worked with the ignition on, so if had heavy passengers in the back seat, sucker would go way up. But came down again if I kept the ignition switch on for about 20 seconds. These later models are always hot.

    Seems like your CVRSS module is not energizing the vent solenoid. I recall with the old ones, like in my 73 Feetwood, could take those apart and clean them, basically a potentiometer with dirty contacts, but not sure in these newer throwaway parts. Looks like the one on my 92 DeVille can also be opened, has screws on it. Some of us remember screws, right? Beginning to think this CRVSS is a dealer only item. Gus should know.
     
  5. leon phelps

    leon phelps Newbie

    Joined:
    Feb 21, 2007
    Messages:
    10
    Likes Received:
    0
    how about one of the relays started clicking like crazy. I had a spare one around 8657 printed on it. Put it in and rear end only went up as far as it should. go figure.
     
  6. nickb2

    nickb2 Wrench. I help when I can

    Joined:
    Nov 22, 2008
    Messages:
    3,256
    Likes Received:
    8
    Gender:
    Male
    Occupation:
    Ex car tech
    Location:
    Québec, Canada
    So what are you saying? Is it fixed?
     
  7. leon phelps

    leon phelps Newbie

    Joined:
    Feb 21, 2007
    Messages:
    10
    Likes Received:
    0
    yes fixed for 24 hours now.

    a relay stuck on, who would have thought it.
     
  8. Gus

    Gus wrench

    Joined:
    Dec 8, 2006
    Messages:
    2,389
    Likes Received:
    0
    Your mission, Mr. Phelps, was to fix that car and you did.....

    Interesting scenario.....if that relay sticks, and makes the compressor run constantly, it will pump and pump and pump......then what happens? Don't know if there is a relief valve in this system.....Not sure if there is some kind of safety built into this system.....it's possible it "unstuck" all by itself before it reached that point.....

    The other thing is, notice the last power input on the right hand side of the wiring diagram? Only hot in run/off? It also says "reset".....so, if you came out to the vehicle, and the rear end was up, if you turned the key to "on", I think that is the reset mode......that vent solenoid should have come on, and the vehicle should have lowered.......but you probably unhooked a line first to lower it.....
     
  9. leon phelps

    leon phelps Newbie

    Joined:
    Feb 21, 2007
    Messages:
    10
    Likes Received:
    0
    my money is on that it pumps and pumps. the rubber boot was rock hard. there was no relief valve that operated. There were two relays clicking, so one could have been the relief valve that was replaced.
     
  10. NickD

    NickD wrench

    Joined:
    Aug 28, 2007
    Messages:
    4,299
    Likes Received:
    0
    Only one relay in the system, for the compressor, difficult to say whether the contacts were welded, but if they were, compressor will always run. Or could be energized by the level module itself. That module does have a time delay built in, have to stand on my back bumper for at least 20 seconds before the compressor starts to bring it back to level. Jumping off the bumper, takes another 20 seconds before the vent opens to drop it back to normal again. Believe there is also a timer so the compressor can only run for a brief period of time. Otherwise with an air leak, it would run continuously.

    Back in 99, when I purchased my 92 DeVille, neighbor dealer let me take it home of three days, was very concerned about the rear shocks, looked rusty. Air leaks are usually the major problem with these things. I did buy the car anyway, and to my amazement, when I got it home, he put two new air shocks in the trunk. 12 years later, they are still new in the box, has been troublefree. More than likely because I have two new air shocks to put in.

    First go around with this system was in a 73 Fleetwood, used a vacuum pump type compressor, tank had rust holes in it, fixed that with solder and a thick coat of paint, then that steel tube had to be replaced all the way back, plus new shocks, and cleaning up that level control. That was a huge car. But nothing like that 89 Continental I was dumb enough to buy with four air struts that went flat. Dealer wanted 750 bucks for each shock! That couldn't be driven period, only about 2" of ground clearance, got rid of that thing.
     

Share This Page