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2002 Deville and 2009 DTS
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Discussion Starter #1
I have a 1998 Deville that I suspect has a bad air compressor for the shocks. Before I take replace this, I would like to locate the ALC relay. I have no manual, but intenet searchs indicates it is in the trunk. I looked behind the carpet ( in the trunk ) and see about 10 relays (sigh) Can anyone tell me exactly which one is for the ALC ? Looking into the trunk there are about
8 on the left side and one on the right. ANY help will be appreciated !
 

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1926 Model T street rod, 2000 Jaguar XJ8, 1999 Corvette.
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Before swapping out a relay, disconnect the height sensor link from the driverside (I think) rear lower control arm. It gently snaps off the ball socket that holds it ( looks like a miniture bar bell ). Then push this link up and turn the key to the run position. Within 10 to 20 seconds you should hear the pump turn on to raise the car. Once the pump runs pull the link down slowly. The pump should shut off. That will verify pump operation. Most problems are with the height sensor not the pump nor relay. The height sensor completes a ground circuit to enpower the pump underhood. This sensor, because its mounted under the car in the elements, tends to have corroded connections and/or failed electronics. The pump underhood rarely comes on and because of this rarely wears out.
 

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2002 Deville and 2009 DTS
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Discussion Starter #3
Actually, I may have left out more info than I should have. I know there is an air leak because when we went on a trip the pump raised the car, but then after about 30 minutes, the car would lower and stay there, until I pull over and turn off the engine, start it again, then the car would rise up again.

So I just assumed either the pump may have finally burned out or the relay did. The car is 11 years old... all orginal parts...

It is too late now but I went ahead and ordered new shocks ($397 a pair) and new pump ($175). So the only thing left to look at after i replaced these are the relay and the lever. If the replacmeent does not work would you get a used lever sensor out of the salvage yard for $35 or a new one for $450 at the dealer ?
Thanks again for your help !
 

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1926 Model T street rod, 2000 Jaguar XJ8, 1999 Corvette.
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After all these parts are replaced, you will still have an air leak. Could be a line or connection. Disconnect that link and shove it up, key in the run position and with a soapy water solution and a brush, apply it to the plastic lines to locate the hole or leak.
 

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2002 Deville and 2009 DTS
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Discussion Starter #5
Will do that this weekend.. Thanks for your input... Plan to leave a note of the results if this works...
 

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1926 Model T street rod, 2000 Jaguar XJ8, 1999 Corvette.
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Should also be a dangling wire on the pump that has a green connector. Thats the test lead for the pump. Simply jumper that wire to the plus side of battery. Pump should turn on
 

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2002 Deville and 2009 DTS
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522 Posts
Discussion Starter #7
OK I put in new shocks and new air pump ( BOY the air pump replacement was FUN !!) now the air pump comes on and the car levels out now... BUT... I noticed on one of the shocks, the rubber boot was rather tight and doesn't slide up and down like the other one does... is this rubber boot ( or rubber sleeve) to keep the dirt out or to hold the air in that the air compressor pumps in there to raise the level of the car ? I am just concerned that the decompression of the shock will eventually cut that rubber and cause it to leak air.
 

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1926 Model T street rod, 2000 Jaguar XJ8, 1999 Corvette.
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The rubber boot does hold the air in. Eventually the boots do deteriorate and leak. most after market air shocks are a better design, and after 25 years the original shocks are weak air assisted or not.
 

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2002 Deville and 2009 DTS
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Discussion Starter #9
Thanks for the pointers... replaced the shocks (from Rock Auto) and the air pump (from Arnott Industries).. it seems to be working fine now. After 1 month, the rubber boot on the shock that i thought was too tight and was not allowing the shock to compress has now worked itself loose and is acting in a normal manner. WHEW....
 
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