dtaylor

My rear suspension has been losing air when sitting. Now the compressor doesn't come on at all. Makes me think a fuse is blown.

I located a 20 amp TEMS fuse under the dash, and looks fine.

Located a 50 amp Air Sus fuse under the hood, and it too looks fine.

Located a 10 amp Airsus 2 fuse under the hood and it looks fine.

What am I missing?

Thank you in advance.

dtaylor

So I replaced the three fuses I found that relate to the air suspension, 50 amp under hood, 10 amp under hood, 20 amp under dash. No change.

Any thoughts?

dtaylor

bump.....looking for help....

BradTank

What happens if you attempt to raise the height on the inside control?

Pull the compressor harness connection and get a multimeter and see if its getting power. You can then troubleshoot it further. You could also take off the negative battery cable and see if resets itself.

Usually the compressor is fine, its the rear air bags that almost always go out. It's just not always consistent. Some days it will sag, other days it's fine. That's when you need to replace the "air springs".

If your compressor went out completely I would think the rear would essentially be collapsed. But you may have let the problem fester until the point blew out the compressor.

There's a lot of systems to trouble shoot, from the bags, compressor, airlines, sensors, relays and fuses, etc.

But if you're having a problem with the rear sagging, I would wager 99% of the time it's because the rear air bags need replacement.

ALAN553

its almost always the airbags, they are the weakest link in the system. They are made of rubber, under the truck exposed to the elements...dry and cracked

dtaylor

It will not raise or lower from the switch, or on its own. Normally, I could flip the switch on the console and raise or lower it. Now nothing happens with the console switch. The dash light does not change, the green dot stays on N. It's as if the switch is rendered inoperable. This is why I changed the fuses. They looked OK, but I replaced them anyway.

Is the jumper wire across the test plug going to do the same thing as disconnecting the battery cable? A reset of sorts? Saw that done in another post to reset the air system. I'll try it and see.

Thank you.

chiph9

When you change the height via the switch, from low to high, do you hear the compressor run?

Chip H.

dtaylor

chiph9, no. I just performed 2 different resets. 1. Battery cable disconnect, reconnect, no change. 2. Jumper wire on ODB plug. Lots of cool action on the dash, and diagnosis stuff on the NAV screen, but no change.

I am coming to the conclusion that I burnt up the compressor, over the last few weeks of reseting, refilling the air springs.

Up to last Saturday, when I used the switch, it made the compressor come on, but now nothing, plus no change in the dash level green lights.

So I will most likely do the coil spring for air spring replacement.

BradTank, I like your steps, and I have not tested for current to the air compressor. I think if I did it wouldn't matter. Either way, I am most likely going to convert. and yes, it is completely collapsed. Riding rough and low down..... you might say....

I find replacement compressors for the LX470 for about $90, whereas the GX470 compressor is $650-$1000. Has anyone been able to use the LX470 compressor? I would think not, or it would be the go-to fix. Just asking.

BradTank

You just don't want to be in a situation where you're throwing expensive parts at it. If you put the compressor harness connection on a multimeter and you're not getting any current, you know it's something else at fault and not the compressor. If you are getting a reading, then you're right its probably going to need a compressor replacement. Did you check the air suspension relay (different than a fuse) in the engine compartment next to the AC port? If that was no longer working, it would no longer be sending current to the compressor.

However, if you're converting to steel coils regardless, then I guess there's no reason to troubleshoot any further.

If you're convinced both the compressor and air bags need replacement, I would agree that a coil conversion makes sense.

dtaylor

BradTank,

Got a pic of the air suspension relay? I may want to check that. I mean I would rather replace a relay than install the coils, however my concern on that is that in order to get the full use of available miles left on this truck, I probably will need to do a conversion sooner rather than later. So, back to that relay....where is it, what does it look like? A pic would be great.

Thank you.

Fr3d

how do you refill the air springs ? Mines been a little bumpy lately but the height controll still works.

Thanks

ALAN553

you don't. The springs are self Leveling. There's a compressor and height sensors which are part of the system...put three people on the back seat, truck drops, sensors detect change in height and start compressor to add air. They get out, truck rises up, sensors detect change and bleed air from springs. Pretty simple. Expensive to repair but still simple.

dtaylor

I decided to convert to coil springs. Bought the Strutmasters kit. $425 shipped. I'll post pics and such after installation. Thank you all for such helpful and timely comments. Glad to be on this site.

dtaylor

I did the conversion last weekend. After a few days driving on the coils, I really like it. What I like more is knowing I won't be bothered by all the what-ifs of the impending issue of whatever the problem is when it starts riding on the axle again... Ride height is slightly north of the neutral height with airbags. I like that too. From the time I bought this truck to now, one of the very best things I've done to it, accept perhaps the 2011 wheels.

Thank you gentlemen for all the helpful comments. You people make it well worth the time benign tis forum, so thank you for that.

deeken

Did the kit come with the shocks too or just the springs? Looking at the website it looks like both. How long did it take to do the installation? Any tutorials you found helpful to do the task? Please share the wealth.
Kindly upload some pics of the truck and close up on the springs if possible. Would love to see how it looks. Thanks a lot.