no backup lights & air ride

[Archangel]

So yeah, today a buddy at work pointed out my backup lights are dead. They were working just fine last week, dunno what's wrong with them now. I was messing with the multi-switch for the lights last friday, is there any chance I've split a wire or something of that sort in the steering column to cause them to go out? Or is there a fuse for them? If they have a fuse, does it by any chance also run the self levelling suspension? Cause that's gone too, was working fine a month ago, but now with 240lbs of sand in the trunk the car sits like an inch lower and the damn thing doesn't even kick in the compressor... Any ideas?

[gadget73]

the air compressor should run off a fuse link over on the fender with the clusterfuck of other wires. Backup light switch is located on the transmission kinda near the shift lever. Probably fused as well but not sure which fuse it is. Check them all is the best advice I can suggest.

[Archangel]

Well, the air suspension system is back online now - the problem was in the height sensor actuator rod, the thing that connects the upper left control arm of the axle to the sensor's arm. It is adjustable, but it's sized for a car riding at close to stock height, so with my cargo coils lifting the rear so much it was actually pulling down on the sensor's arm causing the computer to purge all the air from the shocks. When I loaded the sand ballast in the trunk that caused the car to sink thus returning to factory ride height, which is okay with the air suspension computer and it neither inflates, nor empties the shocks. So to fix that I just made me a new actuator rod, about an inch longer than the original one - when I hooked it up the car went up exactly to the height where she was with the empty trunk.

So yeah, if any of you guys has a lifted car and still plans on using it to haul heavy stuff around this is how you adjust the height sensor:

1. put some weight in the trunk, about 200lbs should be enough;
2. remove the old actuator rod from both the sensor's arm and the control arm;
3. play with the sensor by moving its arm up and down a little by hand until the car lifts up and stays at the desired level;
4. mesure the distance between the two balls the rod hooks up to, compare it to the length of the stock actuator rod, and cut yourself a new piece of threaded rod. The stock one has one end with straight right thread, and the other has reverse (left) thread, but the plastic part can be retapped for straight thread and the given a little help with some epoxy to bond it to the metal rod when threaded onto it;
5. before hooking up the new actuator rod make sure you go and disconnect the harness from the air suspension compressor, this way the car won't surprise you by going up or down the moment you touch the sensor's arm (it shouldn't do it anyways, but better safe than sorry);
6. you're done!

To test the system open the hood, do the key-on-engine-off thing, then go and take all that extra weight out of the trunk - the car should at first lift a little more than normal, then you should hear a 'pop' sound from where your compressor is (that's the purge valve openning) followed by the air hissing and the car dropping to your desired ride height. If you now put all that weight you just took off back in the trunk the car should wait for like 45 seconds, then compressor should kick in and lift her up again. Don't be surprised if you turn the key off and after a minute or so the compressor kicks in again - self-leveling system remains active for some time after the car has been shut off (1 hour for newer vehicles, dunno about boxes), so it working will come to say that you have an air leak somewhere and you might want to go ahead and fix it before you burn your compressor out while pulling or carrying the next pile of junk.

Hope someone finds all that info useful...