Really embarassingly basic air suspension question

So the compressor fuse keeps blowing, which i take means the compressor is broken and needs replacing or rebuilding.

Now the stupid question is: the ELC fuse keeps blowing too, will this be fixed by replacing the compressor or does that module need to be yanked out from above the axle?

Are you referring to the A/C compressor fuse in your first sentence? I believe that the fuse for the A/C compressor is for the clutch.

What year car do you have? 91-93s have the ELC compressor where a car with dual exhaust would have the left muffler. The 94-96 compressor is behind the right front bumper. If the fuse is blowing for that compressor, the compressor is probably locked up, and the motor is fried.

1995 RMW LT1

The “compressor” fuse is labeled “air” and then there’s a separate fuse labeled “ELC”

Both of those fuses blow as soon as you turn on the car.

What I’m trying to figure out is the extent of the problem.

You should consider getting an FSM. You will find the wiring diagrams in it. I believe the Haynes Manual has a wiring diagram in it too.

Ok, first problem is you are confused on what the fuses actually are

ELC is for the Electronic Level Control, meaning the Air Compressor.

The fuse labeled AIR has NOTHING to do with any compressor. That is for the A.I.R pump, part of the emissions system. The pump is most likely busted so just unplug it. GM knows the thing is absolutely useless and disabled it via recall at some point. Very few people have one that actually works

Without the AIR fuse your under hood light should be out as well.

The "Module" at the rear axle is the leveling valve. It inflates/deflates the system as needed.

Most likely you have a fried Air Compressor because like most everything else 90s GM, they are low quality and decades old now.

94Woody wrote:

Ok, first problem is you are confused on what the fuses actually are

ELC is for the Electronic Level Control, meaning the Air Compressor.

The fuse labeled AIR has NOTHING to do with any compressor. That is for the A.I.R pump, part of the emissions system. The pump is most likely busted so just unplug it. GM knows the thing is absolutely useless and disabled it via recall at some point. Very few people have one that actually works

Without the AIR fuse your under hood light should be out as well.

The "Module" at the rear axle is the leveling valve. It inflates/deflates the system as needed.

Most likely you have a fried Air Compressor because like most everything else 90s GM, they are low quality and decades old now.

Thank you!!! That makes a lot of sense.

How involved is swapping the suspension compressor? I know it’s under the air filter, I can kinda see it. Is it a plug-and-play sort of deal?

I just removed mine so I can put duals on my OCC. There is a pressure line connector, electrical connector, a rubber line with a "T" in it, and three bolts with 13mm hex heads. The bolts come out first, with the hidden one as the priority. A socket will not fit between the frame and the bracket, so grab your ratcheting box end to remove it. You will also have to take the antilock lead out of the standoff to get one of the bolts out. My compressor is still good, because I disconnected it years ago when the shock bladders broke, and while it still ran. Now, I no longer have room for it.

The 94-96 is behind the driver's side front bumper, and probably has 3 bolts and similar connectors.

Mine was pretty simple to remove and toss into the trash can.

I saved mine in case someone needs a good one, or if I decide to get another OCC, and it needs one.

Mine was full of sand and blown up so garbage was the only option

just bought an apparently working compressor for my 96. It runs, but hasent seen pressure yet. Probably going to go with the air shocks. Rock Auto shows 2 versions, slight price difference. Is the "limited" model actually different, or is it just a label?

ACDELCO 504511 {#88946598} Specialty; Air Lift; Sold In Pairs Info
Rear; Limited Collector's Edition
$73.79

ACDELCO 504516 {#88946603} Specialty; Air Lift; Sold In Pairs Info
Rear; Estate Wagon Collector's Edition
$75.79

The limited may be a little softer, because I believe they came with a dynaride suspension that isolated you from the road even more than the standard suspension.

Thank you Fred, that makes sense.

The *511 kit is listed by AC Delco as for Sedans. The *516 kit is listed as for Sedans and Wagons. I have no idea what the difference is.

Isurf wrote:

just bought an apparently working compressor for my 96. It runs, but hasent seen pressure yet. Probably going to go with the air shocks. Rock Auto shows 2 versions, slight price difference. Is the "limited" model actually different, or is it just a label?

ACDELCO 504511 {#88946598} Specialty; Air Lift; Sold In Pairs Info
Rear; Limited Collector's Edition

$73.79

ACDELCO 504516 {#88946603} Specialty; Air Lift; Sold In Pairs Info
Rear; Estate Wagon Collector's Edition
$75.79

@Isurf -- which AC Delco rear air shock did you end up going with? From the specs on Rock Auto, there are several differences between the 504511 (aka P/N 88946603 which, AFAICT from Summit Racing, is for sedans only) and 504516 (aka P/N 88946598 which, again according to Summit Racing, is only for sedans) -- see the info forlower mount, compressed & open lengths, and shock stroke in the RA spec sheets below.




Note that the GM GENUINE 504110 (aka P/N 19178430 -- which Summit lists as OK for both sedans and wagons) is also available from RA, and that RA  tags for cars with the G67 self-adjusting suspension:

That compressor is still sitting on the "someday" shelf.