On my 2004 Yukon XL Denali my air ride service soon was on the dash so I bought a new Arnott replacement. I rebuilt the dryer to spec I did everything they wanted me to do and I just installed it and it wont pump like it used to could there be a relay that is not working or a fuse. I checked the 30 amp Fuse name RTD because I thought that was one I heard from a friend and that was OK. I guess the only thing I didn't replace was the crusted up ground from the Old air compressor on to the new one. Would that ground cause it not to operate. Or is there a relay that I need to check that is causing it from pumping. Its brand new. I crimped all the wires that needed to be crimped from the old one to the new one. Turn on the key and I don't here it pump and I get the service air ride error still. Can you think of anything else I can do to get this to run. I can only think of a fuse or a relay because I was very meticulous on repairing the old compressor. I always am when it comes to car parts. I crimped the wires and then put them in the sheath and taped over it for better protection. I got the hoses installed securely but that would have nothing to do with the compressor not running would it?? Could someone help me out with which relay is for the air ride or which fuse I need to check to make sure I have everything OK from the vehicle side of things. and if everything is OK from that side then I have to unhook the compressor again and double check everything and connect that ground wire but I don't know where that connects to the compressor but the compressor should be grounded through the mounts and being anchored to the frame. Can anyone help me please. Im begging here because I have a bad back and its pain getting under the Denali and working around the tire and trying to stand up after Im on the creeper. I would love to get this checked off my list. I would be in your debt if you can help me get this running, please anyone who can help me. I would be so gracious.

i doubt it is supposed to ground through the frame because that would not be a very good connection. the bodies get a bunch of rust and it wouldnt work. so you are saying it had a ground wire that you didnt put back?

Yes its a ground wire that is connected to the compressor wire box and then connected I think to the compressor but Im not sure it should be on the compressor somewhere. The wire is all tarnished with corroded ends and it had to connected to the compressor or dryer screw do you think this could be the main source of the compressor not kicking on?? Thank you for the reply!!

Would the ground from the compressor J-box that is not connected. Could that not allow the compressor from not working. Ill unmounts it again and make a new wire ground connection to the compressor and I hope that works and also would you happen to now where the relay is for the compressor. Thanks and take care. Jonathan

I need help because I spent a lot of money on the compressor that I need to get working. Thank you so much I need all the help I could get,

you will have to make a new ground clean the frame to bare metal and the spot you put it on the compressor. hook it up and put some dielectric grease on it

You could try running a redundant ground all the way back to the battery as a temporary means of seeing if that is the problem or not.

Yes grounds are on the frame. There is one that rusts in pieces that actually goes to the ABS Module and will cause problems.

I would get the code pulled for the Chassis. that way you know what direction to go. Usually the compressor and all gets replaced. its sold as one part.

Also it is commonly the exhaust check valve that is defective, which is a part of the whole asm. Why and what led you to rebuild the dryer?

The Kit that I bought came with a new compressor and a rebuild kit for the dryer. I had to put a mesh screen in, then a soft round piece of cloth and then desiccant beads then another mesh screen and another piece of cloth, and then a new spring and then I screw the top back on to a torque specification. Install a new O ring into the compressor and set the dryer on top where its is suppose to go with a new O-ring. The cut the wires from the old compressor and crimp them together with the wires from the old electrical connection. Which I did and connected all the were connector'* and hoses and it should work right? Wrong, What do I need to do?

how about power from the plug? Also new parts can be faulty out of the box. I would try and see what Chassis code you have also. that will help lead in the right direction.