So, as the title says... I went out to my Disco this morning ('03 HSE) and my driver side rear air suspension was completely out... and the right side looked as if it was rather low as well. I started it up to see if the compressor would kick on but it never did.

Any ideas??

I'll put her up on the jackstands later to check things out...

 

bad compressor maybe? you could take a voltmeter and test if it's getting voltage..i'm guessing it should be getting 12v but not sure.

 

Its your height sensors. Or a air leak.

 

Take some soapy water in a spray bottle and with the truck running spray it around your air lines back by the airbags.
If it bubbles you have a leak.

 

but wouldn't his compressor still come on even if the bags were leaking? I have one that leaks down after several days but the compressor pumps it back up.

 

Yes the compessor would still come on if there was a leak, unless the height sensors were bad.

 

Will the truck level out when you start the engine with your doors closed?

 

Na, the compressor doesn't come on at all. This is the first time it's ever happened.

If the height sensors went bad, wouldn't I have some sort of warning lights on?

 

Nope, no warning light. Just one of the joys of having SLS.
Your on the trail 50 miles deep into the woods and your airbags go flat and you have to limp it home on the bump stops.
Coil spring converstion and no problems for the rest of the trucks life.

 

would it be possible for him to take the height sensors out of the circuit and then complete the circuit without the sensor?