View Full Version : Suspension Compressor 07 EXT

11-15-10, 11:32 AM
Where is the compressor mounted for a 07 EXT? I have heard it is in the rear drivers side wheel well? When I first got my truck I would hear it all the time working. How do I test it to see If it is working still?


11-15-10, 06:11 PM
I'm not positive on the location but an easy test is to have someone sit on your tailgate while you start your truck. If they weigh over 100lbs it should trigger the compressor within a few seconds.

11-15-10, 07:21 PM
The compressor should do a self test after the key is turned to the on position after about 20 seconds or so. It should turn on for about 5 seconds then exhaust. HTH.

11-15-10, 10:03 PM
I never hear it do that! Would I get a light s not working?

11-15-10, 11:56 PM
To test it, put something heavy in the cargo area (my golf clubs and push cart usually kicks it off). Let it sit for a few hours. put the key in and turn the ignition on, but don't start it (so you can hear the compressor). You should hear it kick on to level it.

11-16-10, 12:27 AM
So the truck has to be off for it to self level or kick in? Or it will do it when truck running?

11-16-10, 01:48 AM
If you really want to test it. While the truck is off, load ten 100lb sandbags. You should notice a decreased ride height, now turn the car on. You may not hear the compressor but you will notice the truck level.

My suggestion is just that, a suggestion. In no way am I representing that I know what I'm talking about. If your truck breaks or if you break your back don't come looking for me.

Good luck

11-16-10, 12:01 PM
Thanks for all the help on this. Does anyone know if the truck self levels its self if the truck is all ready running? Do you get a light if the system is not working properly?

11-16-10, 08:20 PM
It works when the truck in running. If a problem occurs in this system, you will get a "service ride control" message on your dash.

BTW- check your fuse under the hood. I had mine blown and it did not give me any messages. It's a 40 amp green square fuse. The reason that it blew was because one of the shocks were leaking, and it caused the pump to run constantly, until it blew the fuse. So I would also check the shocks in the rear. After you get the compressor going and the system builds pressure, feel the rubber bladders on the shocks after letting the truck sit for a while with the key off. The should hold some air. If not, the shock(s) may be leaking.

11-17-10, 08:43 AM

11-17-10, 12:48 PM
I checked fuse it looks good. I tried to stand on back bumper to get pump to kick in but couldn't get it to kick on. So no blown fuse and no light?

11-17-10, 09:13 PM
You checked both? Fuses 54 and 61? There is also an ALC relay on the side of the fuse box that may need checking.

11-18-10, 10:36 AM
Checked #2 #54 #61 all fuses good. where is the ALC relay on box?

11-18-10, 10:01 PM
Looks like it's clipped on the side of the underhood fuse block. I would see if it clicks after the ignition is turned on after about 20 seconds.

11-23-10, 11:53 AM
K I bought a new snow blower the other day loaded it up on truck its heavy! And truck was sagging on the back so level system is def not working.

11-25-10, 09:22 AM
Where are you located?

11-25-10, 08:06 PM
Winnipeg, Canada

11-25-10, 09:31 PM
Ok, here's the deal. Everyone is making this sound way more complicated than it is...

Leave your car off for a few hours, don't play with it, don't turn on just the accesories, don't unlock/lock... Just lock it, walk away for a few hours.

Come back to your vehicle, hit unlock, walk inside. Now put in the key, and turn to on. When I say "On", I don't mean accessories, I don't mean "Start" (we don't want the engine starting so it's easy to tell), I mean just "on".

Now make sure your in a quiet environment (even though it should be loud and you should be able to hear it).

After 5-10 seconds after turning the key to "On", you'll hear the pump (like someone else mentioned in this thread). Since you didn't actually start you vehicle, it'll be one of the only two mechanical sounds you'll hear (it's not that laser sound that the fuel pump or whatever makes very quietly, or whatever it is).

Hope this helps. And trust me, it is loud, so if everything is quiet, you'll know when you hear it for sure.

I can turn my vehicle fully on (starting the engine), and can hear the compressor filling up. I noticed that it always happens when the vehicle has been off for some time... Sometimes it does NOT happen when the vehicle was just on 10-30 minutes ago.

11-27-10, 11:39 AM
If he loaded a snow blower in it and he started it and that compressor did not turn on, there's a problem. I was just helping him through the basics.

11-27-10, 12:04 PM
I dont think the system runs itself through a self test at every startup like the EGR system does. I could be wrong but I'm pretty sure the pressure transducers dont exist for this. If it did, then poster who blew fuse would have thrown a code.

You did everything correct. Sounds like the compressor motor might be shot. At the very least, get under there and make sure the electrical harness connector is on good and tight.

11-27-10, 03:41 PM
Thanks for all the input guys I will double check everything again but I think the pump is shot. Does anyone know if this is covered under warranty?

11-27-10, 04:31 PM
yup... bumper to bumper warranty covers the ALC compressor... we change them out a bit (at least enough to stock one or two)

11-27-10, 10:39 PM
Thanks my bumper to bumper ended I guess powertrain does not cover it. I do have a extended warranty so guess I will have to go that route.

12-02-10, 05:53 PM
I just got back from dealer. Sure enough compressor is shot! Also both rear shocks bags are toast! Which would explain why the compressor is dead. Anyway extended warranty covers compressor but does not cover the shocks. Total cost for new rear shocks $2300 bucks.

12-02-10, 08:25 PM
i can save you some $$$ on those if you decide to get new OEM parts

12-04-10, 09:14 AM
Thanks, But I'm going to fight the dealer on this one. I have not had the truck long and this was missed by the 190 point inspection. The compressor has never worked from day one. No light on dash to show there was a problem with the suspension. Its quite common most people don't even know the rear bags are leaking.

12-04-10, 09:24 AM
Let us know how it goes. I'm somewhat surprised to hear that these fail. I used my 2003 EXT as a truck for the last 4 years of my 7 years of ownership. Never had a problem. It would run for an extended time after the addition of a heavy load, but it never failed to complete the leveling.

12-04-10, 09:41 AM
I've replaced many compressors doe a c0660 code for exhaust solenoid failure. Cannot get solenoid seperately.

12-04-10, 10:31 AM
I just spoke to dealer and they agreed to cover the cost of install and new shocks. I will only have to pay my ded for my extended warranty for the compressor. $100 dollars out of pocket. Thank god for a good dealer.