Auto-Leveling compressor location

Hi all-

I know this may seem like a dumb question to many, but, where exactly is the auto leveling compressor located on a 1994 Roadie wagon? Prior owner removed it and I want to reinstall. In the past year, I have found exactly 4 wagons in the self service wrecking yards and nothing newer than 93's. I just pulled the compressor off the bottom of a 91 along with the control arm and wiring. I just read now that for the LT1 models that the compressors were not located on the bottom drivers side rear which is where I finally got one from.

My wagon currently out of state so I do not have benefit of looking underneath it right now but I recall there was a space that looks like it held the compressor behind the drivers rear area.

If it is actually up front somewhere, I have never seen one in a yard car. If it is, I will have to keep scouring for one in a yard as when the Roadie is back I want to get to this project. Just saw a 96 Roadie Sedan in the yard but it was striped clean.

Anyone know what the actual is and maybe a photo or diagram?

The LT1 cars had their compressors under the hood I thought. Also, someone can feel free to correct, but aren't the compressors the same 91-96 just mounted differently?

LT1 is under air filter roughly if I remember right.

The compressor is mounted under the wheelhouse on the passenger side, under the battery, or the driver's side, under the computer. You have to remove the plastic wheelhouse extension to get at it. It is in the corner behind the bumper cover. I have not had one apart for a while and I forget which side it is on.

Thanks Fred. I will have the wagon back in a few weeks and will immediately check this out then. I found searching the internet a while back, a guy who figured out how to wire (at the compressor) it so the compressor only works with the ignition on. I have tried numerous searches now and cannot find the info.

Any idea on this one?

It is in front of the drivers front wheel, under the plastic wheel cover. Mounts to the frame with 3 bolts (17mm)

Wagoninabox wrote:

Thanks Fred. I will have the wagon back in a few weeks and will immediately check this out then. I found searching the internet a while back, a guy who figured out how to wire (at the compressor) it so the compressor only works with the ignition on. I have tried numerous searches now and cannot find the info.

Any idea on this one?

Get rid of the wire from always hot that powers the compressor and and use a switched source?

I'm curious why people want to de-energize the compressor? It doesn't do anything when it's just sitting unless you have an air hose leak or put weight in the car. The compressor circuit has to be energized after you shut off the car because after the weight is out of the car it takes at least 8-15 seconds for the compressor exhaust solenoid valve to activate to release air from the shocks and lower the car to normal height, won't if you switch the power off with ignition. Mine sounds like somebody giving a raspberry or burping when it releases, could freak you out if you didn't know what it was.
If you don't want it to work with the car off get a battery disconnect switch for the battery ground terminal and shut the whole car off. I put one on mine first thing after I got it, do on all my cars, near everything in the FSM says to disconnect the ground before servicing and it makes things a lot easier, good to just shut the car down when parked for a while too.

Great information, Thank you.

Al H. wrote:

Get rid of the wire from always hot that powers the compressor and and use a switched source?

I'm curious why people want to de-energize the compressor? It doesn't do anything when it's just sitting unless you have an air hose leak or put weight in the car. The compressor circuit has to be energized after you shut off the car because after the weight is out of the car it takes at least 8-15 seconds for the compressor exhaust solenoid valve to activate to release air from the shocks and lower the car to normal height, won't if you switch the power off with ignition. Mine sounds like somebody giving a raspberry or burping when it releases, could freak you out if you didn't know what it was.
If you don't want it to work with the car off get a battery disconnect switch for the battery ground terminal and shut the whole car off. I put one on mine first thing after I got it, do on all my cars, near everything in the FSM says to disconnect the ground before servicing and it makes things a lot easier, good to just shut the car down when parked for a while too.

You could get the best of both worlds by installing a delayed release solinoid (you can get them for up to 2 minutes) that is activated with the ignition but the thru power is still hooked up to the factory fuse.

Bill

Wagoninabox wrote:

Thanks Fred. I will have the wagon back in a few weeks and will immediately check this out then. I found searching the internet a while back, a guy who figured out how to wire (at the compressor) it so the compressor only works with the ignition on. I have tried numerous searches now and cannot find the info.

Any idea on this one?

That was in the ISSF wagon forum. Gerry "95wagon" swapped wires C and D at the level sensor by the rear axle. He said that his only problem was that his car never vented, so the tail got high when parked.

I didn't have any luck, and put the wires back. My problem later turned out to be an intermittent open circuit. Because of that, I was never able to get test the mod.

http://www.impalassforum.com/vBulletin/showthread.php?t=250848

Thanks Krzdimond; I will have my rig next weekend so I will be attacking the auto level.

Al H. I wanted it to be only with the ignition as I have read countless dead battery stories by leaving it factory. Since it is always "hot", things like tempeature can cause it to activate (heat build up, etc) other than air leaks and I do not want to be caught with a drained battery if I can prevent it.

Nick Thanks. I finanly found the ISSF fourm that had the write up. There are two procedures listed, either to switch the two wires or to rewire the "always on" to the wire that is "on with ignition". I plan to wire the sensor to "on with ignition". If there is heat build up or it is to high or low, when the the car is first turned on, the system would check this an adjust as necessary, at least that is the way the system is suppose to work.

I bought an under body auto-level compressor off a 93 RMW at a wrecking yard and I am going to mount that one in the space that held it in years prior to 94. I will power it from the wires feeding the engine compartment auto-level compressor (at the rear sensor for ease of splicing) and wire a switch beneath the car for on/off. This way I will have an on-board inflator for my tires and and such. A curly cord air line is easy enough to store for this.

Can that compressor on the LT1 be unplugged and taped-off without removing the wheel-well plastic? I have not gotten under my car to look for it yet.

Issue is I had pulled the relay for that compressor years ago when I got rid of the air shocks. Well now since installing the electric fans, and the relay and fuse in the box under the hood, I noticed my compressor came on last night....first time in years!

Air shocks are long gone and I just want to unplug the compressor.

-Mike

The plastic shroud has to come off to unplug at the compressor. It means taking the wheel off and 15 minutes to take the shroud off and that's it.

Doh. Ok thanks for letting me know.

Adding this to the project list.

-Mike

Here is the link to the Impala forum that discusses how to change from "always on" to "on with ignition".

Took me a while to find it but now I'm going to try the "swap wire C and D" trick.

http://www.impalassforum.com/vBulletin/showthread.php?t=250848

I've got a leak but this will at least let me keep my battery charged until I come up with a solution.

I've still not unplugged mine. It's on the 2-do list.

I just unplugged mine and will need to figure out what to do next.  It isn't going to be easy to do the swap unless I take the level sensor out of the car.  

I guess my car has the factory setup.  I don't see any bags inside the springs but I do have air shocks.

Probably going to have to take it to my repair shop.  I wonder what will happen if I just leave it disconnected?  

I'm thinking if I do that, I'd better tape up the connectors on both end so they don't get exposed to dirt and water.

My compressor is near the rear axle.