FAQ: Automatic Leveling Control (ALC) Concerns

Mine burned out after a leaking line caused it to run constantly.

Hey for the first time while letting the car run while cleaning snow off the windshield and rear window, I could actually hear my pump running. Amazing, it is alive under there.

I was wondering if there could be alink somwhere my front passenger
heated seat stop working around the same time my air ride pooped
out .Also the little lite in door handle on passenger side is out .
that side of the car also seems to be the lowest Does anyone have
clue to my problems .Thanks

check your fuses under the back seat. run an ohm meter across them and replace any that are out.

AA wrote:

Mine burned out after a leaking line caused it to run constantly.

Precisely the reason why those dashboard dummies should have used the blank spot, the duplicate low-washer-fluid spot, or the unused brake-to-shift spot for Trunk Ajar and Level Ride lights...

Seriously, now that I've traversed the path from the trunk to the dash for the sequential signals, I'm gonna' run another zip-cord from the trunk to the cluster if I ever have to take the upper dash apart again.

My pump seems to be a lot louder when its cold out but I'm not touching it... The whole air suspension thing back there can keep doing its thing. *keeps fingers crossed*

DEMonte1997 wrote:

My pump seems to be a lot louder when its cold out but I'm not touching it... The whole air suspension thing back there can keep doing its thing. *keeps fingers crossed*

Agreed lol

Well I just read through this thread, and while it is confusing, I understand how the leveling system works now. BUT, now i have a question. My fuse and relay is good for my air compressor (a '95 - under the passenger side) but my compressor still doesnt seem to run. I know i need new rear shocks but they don't leak as they've been the same height since I bought the car. The air lines from the compressor to the shocks look good, and the wiring is pretty clean. However, the compressor itself is a bit rusty. I'm assuming this is the system's point of failure. I know i can take the compressor off and put power to it to test it, but I don't know how to uninstall it. Does anyone have detailed instructions on how to disconnect this sucker? I saw there was a post with pictures but the pictures don't show up.

Still a newbie at this, hope I'm not being obnoxious!

Andrew,
I don't know if there is any difference from the 1998 to 1995 as far as mounting arrangement, but I will look in the 98 FSM and try to post what I find.
I took mine out before having the manual and the only difficulty i encountered were rusted bolts and the heat shield that cover's it was no longer usable after removing it, it was very corroded.
At the time i wasn't aware of this site and just did a search and found Morads for a replacement compressor assembly and good shield. Turned out I didn't need a whole new pump, but that's another story.
I'll see what i can come up with for directions on removal and installation and testing.

Z-type wrote:

BUT, now i have a question. My fuse and relay is good for my air compressor (a '95 - under the passenger side) but my compressor still doesnt seem to run. I know i need new rear shocks but they don't leak as they've been the same height since I bought the car.
The height of the car could be maintained by the springs and not the shocks. You will know this when you put weight in the trunk or passengers in the back seat

The air lines from the compressor to the shocks look good, and the wiring is pretty clean.

The air lines can look good but have cracks as they are plastic or the o-Rings that seal the ends of them can be bad.

However, the compressor itself is a bit rusty. I'm assuming this is the system's point of failure.

Don't automatically assume the compressor is the point of failure.

I know i can take the compressor off and put power to it to test it, but I don't know how to uninstall it.

You don't have to remove the compressor to put power to it. You can gain access to the plug that powers it by removing the heatshield only. Just 3 or 4 screws from what i remember


Does anyone have detailed instructions on how to disconnect this sucker? I saw there was a post with pictures but the pictures don't show up.

Still a newbie at this, hope I'm not being obnoxious!

You could use a wiring diagram more than the description of how to remove the pump at this point. I believe the 1998 diagram I have is the wrong one for your car. i don't want to further confuse the issue.
You need to find the 95 diagram. Can you work from wiring diagrams.? Not trying to be a dick but some people have a hard time deciphering wiring diagrams.
I may be able to get the 95 diagram posted on here for you, if someone else with a 95 can't help sooner.

I assume you have read through all the pages on this post as i just did. it will give you some understanding of the system and hopefully the wiring diagram will help you understand the rest.
Let me know about the wiring diagram and your ability to decipher it before i try and find and post it. OK,
Rick

I have tried to resize this, but am unable.
It is 1995 wiring diagram of ALC System. Maybe you can take it and do something with it. If not let me know and I will try again.

Z-type wrote:

Well I just read through this thread, and while it is confusing, I understand how the leveling system works now. BUT, now i have a question. My fuse and relay is good for my air compressor (a '95 - under the passenger side) but my compressor still doesnt seem to run. I know i need new rear shocks but they don't leak as they've been the same height since I bought the car. The air lines from the compressor to the shocks look good, and the wiring is pretty clean. However, the compressor itself is a bit rusty. I'm assuming this is the system's point of failure. I know i can take the compressor off and put power to it to test it, but I don't know how to uninstall it. Does anyone have detailed instructions on how to disconnect this sucker? I saw there was a post with pictures but the pictures don't show up.

Still a newbie at this, hope I'm not being obnoxious!

It's the point of failure in *your* case. IIRC most of the failures are from worn out shocks or road debris splitting the lines and the compressor runs too much.

It would be a good and inexpensive bet to just get a good used compressor from Ed Morad, [url]moradpartscompany.com[/url].

Albertj

i have a compressor for sale too. rust free, from a FL car.

Thanks guys...and thanks Rick for correcting me on a few of my assumptions - I was typing and thinking quick! And yes that diagram will be very useful! My neighbor has a lift so this should be easy to work with/on once I get a hold of him.

The main reason I think it's the compressor (without testing it first) is because i know for a fact it doesn't run under normal conditions. I messed with that 'leveling' sensor bar - nothing whatsoever. Anywho, I'll go over that wiring diagram and Mr. Riv, I may be getting a hold of you! Thanks!

Mr.Riviera wrote:

i have a compressor for sale too. rust free, from a FL car.

You want to trade a Snow Blower for it.
Works real good and will last you a Lifetime.

Rickw wrote:

Mr.Riviera wrote:

i have a compressor for sale too. rust free, from a FL car.

You want to trade a Snow Blower for it.
Works real good and will last you a Lifetime.

you know rick, i actually had to google 'snow blower' b/c i've never seen one.
i'll stick with my light jacket and flip flops

Now that you've seen one, you just gotta have one around.
It's a real good deal I'm offering you.
You just never know when your gonna need it.
With Global Warming causing all the freezing activity down South and all, just saying.....you'll be sorry!!!!!!

Going once, going twice.....going twice....

Andrew, I had recently had to fix my ELC .
While poking around the level sensor with a grounded test light to see if there was power to both the pins specified in Ricks diagram(key on connector disconnected, car side) I hit the yellow wire and found I could command the pump relay to close(test light created a ground path) and caused the pump to run.

My case was a hidden broken wire to the "hot at all times" fuse, no power on that pin even though the fuse was good.
Quick fix was to tie the key on power to the hot all times, no real load on those circuits at the level sensor so I figured it was safe .. its still working 2 months later.

Grab a cheap test light check for the 2 powers then poke the yellow wire to see if the pump runs.

Ed points out a good example of the many things that can stop a compressor pump from coming on. Even if you move the control arm up and down.
If there's no power going to it or if the exhaust solenoid is stuck open or the exhaust port is clogged, or the exhaust solenoid is bad. Could go on and on.
It's a simple system with a lot of small components.
Need to check it all out before buying parts. Although i have decided to have an extra compressor because i know how harsh the weather is up here and these do corrode.
The cylinder heads on them are aluminum and produce a white powder of corrosion that can block the exhaust port. That's what i found on my original one. The way the system works is it won't let the compressor run continuously like the Caddy's. It's on a timer, so if it hasn't reached it's commanded height by a certain amount of time it will shut the compressor off. But everytime you turn the key on it starts the cycle over again. As it turned out mine had two problems, one was the exhaust port was clogged and it had a wiring issue. Took a little diag time but problem solved, 3 years ago and running good with new shocks.
So when I had the opportunity to buy a spare compressor for reasonable money I grabbed it.
Watch, now I will never need it.
BTW, have you got the 95 FSM or access to Alldata or Mitchell for any technical info besides the wiring diagram?
I have access to some data for the 95 , but am unable to print and scan it for you.

I went through the diagnostic chart in my 98 FSM. It took me awhile, but I was able to narrow it down to one broken wire. I would have never been able to find the problem without the FSM.

Here, here. Another proponent of the FSM.
Can't seem to drive home the need for a FSM while diagnosing, enough.

Hi: I have a 97 and my alternator went bad. After that the rear went up about 3 inches! Is there a purge valve on the shocks? Any ideas on getting her back down?
Thanks

The two things have nothing in common. Just a coincidence.
The compressor for the rear shocks has an exhaust solenoid on the cylinder head of the compressor that can go bad or the port that it exhausts out of can get clogged preventing it from dropping the rear.
The electronic control switch mounted on the drivers side rear chassis and connected to the left rear control arm can go bad also.
There is a method of troubleshooting this problem that is relatively easy in the Factory Service Manual or Alldata or Mitchell.
What ever source of tech data you have available to you will explain how to solve it. It is not expensive either to fix the system on the Riv compared to some other cars.
once you determine what has gone bad you can find used parts relatively easy as well.

Here is a bunch more info.
http://picasaweb.google.com/brianesser76/SteeringAndSuspension#