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Answer the 1Million Question: Where is the air ride control relay located?

329K views 438 replies 100 participants last post by  Submariner409 
#1 ·
My friend has pretty much troubleshooted my no "compressor on" problem to the relay on my '02 EXT. We used a test light to the power (red wire) going to the compressor and we could not get anything. I stood on the back bumper trying to activate the compressor and we got no power. So I went to the local Autozone and the only info they had in the computer is that the relay is possibly located under the driver seat.

It's a pigtail relay, Niehoff part # PS38281 "Accesory Relay Connector". It's a plug with 5 wires coming out of it.

Can somebody please tell me where this is located in my 2002 EXT? Thanks in advanced.
 
#245 ·
Ur best bet would be to replace the assembly with an Arnotts'. But I would still try to revive this one (I'm cheap...)! If you can make the motor run again make sure to take a look at the exhaust solenoid. Corrosion must have severed the 2 wires in there. Using jumpers, test solenoid operation while the assembly is still off the truck via the round connector. If motor and solenoid are functionning, ur good to go!
 
#248 · (Edited)
This is a great thread with a wealth of knowledge. My compressor quit running upon start up of the truck, I could jumper the relay contacts and the compressor would run. I removed the compressor and found the exhaust solenoid coil open. I believe the computer looks at the condition of that coil to give the compressor a start, since most every compressor likes to start unloaded when possible. A new one came from Arnotts the next day. I removed the old connector and bracket and mounted it to the new compressor. Spliced the 4 wires color for color. Arnotts also sends the rebuild kit for the dryer (step by step with pictures...god I love pictures) Rebuilt the dryer (old one had moisture and the guts were end of life) and reinstalled the unit. Started the truck and found the new unit was much less noisy than the old. ( Thanks to an enhanced design of the rubber mounts) Air ride works with no alarm. Great to see quality being built in the US. I'm glad this thread was here, I studied it a lot before spending about 200 for a new compressor........Thanks Guys
 
#249 ·
Thanxs for the update! You are correct about the function of the exhaust solenoid. I should have a look at the dryer on mine. I fixed the solenoid but didnt pay attention to that. I would not hesitate on an Arnott unit if catastrophic failure happens!
 
#250 ·
ok, another new member of the forum here :) after spending much time readung through everyone's problems - and congrats to those who have found solutions to there's...I am still, as well as my dealer, dumb founded with my issue. My compressor was tested and works. Shocks and lines have no leaks. Truck turns on, within 30 sec compressor kicks on, rear lifts...i attach our trailer and rear end never auto levels out...ugh! Any thoughts?
 
#258 ·
I would start with removing the relay and jumping the wires to see if the compressor starts up if so, then try the jumper again with a load on (trailer hooked up) and see if it still comes on and lifts. If you start from the beginning on this thread it will give details on jumping the wires to test it out.
 
#253 ·
Just wondering if anyone has figured out how to make the SAR light shut off?? I just replaced the rear shocks with gas shocks due to EVERYTHING being bad and if I unplug the fuse under the hood the SSS light appears. Is there anything that can be unplugged or a resister in place of the unplugged shock plug?? thanks
 
#259 ·
Fitz13: The only reference for the SCM to command the compressor on is thru the back level sensors. Did you buy this truck new? Has it been lowered? Hooking up a trailer, passengers getting in the back, filling up the tank, even hard acceleration will cause the compressor to turn on and level out the back end. My guess would be that the level indicators are working at the low end of the 0-5V reference. Your dealer can verify this data with their Tech2 scanner. If there was an electrical problem with the compressor, the SRC light would come on after you hookup a trailer. Btw welcome!!!
 
#261 ·
After reading all the threads about ride control system problems, I was able to fix mine in less than two hours, thanks everyone who posted their comments. In the end my problem was the coil wire had broken on the exhaust solinoid. Solidered it back and the system works like new.
The ride control relay on a 2003 Escalade IS located under the fuse panel under the hood.
Thanks again to everyone who spent hours working on this problem.
 
#263 ·
I would like to thank everyone how participated in this thread I was having this problem for almost 2 years if not more? I t was the exhaust solenoid the white wire broken and it was not open circuit when checked? But still I decided to open it after soldering it everything worked fine .thank you thank you thank you.
 
#264 ·
Hello to everyone who have post on this thread i have read through all 18 pages cause i have somewhat of the same problems. My 03 ext has a src but i can hear my compressor turn on everytime i turn on my truck,the src pop up soon as it start driving. so could it be something else or can it still be inside of the compessor that the problem.Also mine didnt start coming until my wife drove home on a almost complete flat tire since she wasnt far from the house and it hasnt gone off yet (3wks now).Could it be the scm need to be reset.Thanks to any advice in advance.
 
#265 ·
Welcome GaExt! There is a code that will trigger the SRC error message if the compressor runs for a set time without any change in the ride height/pressure. How long does the compressor runs for? Does the back end raises up? If run time is reasonable, say 20-30 seconds, the pressure sensor or level indicators are probably faulty. At least you know the solenoid is ok lol! Post back ur results.
 
#267 ·
I would guess the two rear level indicators are not sending the same values to the SCM. Do you have a good digital multimeter? First check to see if the level indicators are not broken, or rods bent (rear inner wheelwell, towards the front, cant miss em). Did you fix the flat tire yourself? Maybe the level assembly was damaged in the process. If all is well you will need to measure the voltage at the SCM before and after compressor run time. Same for pressure sensor indicator.
 
#271 ·
Well, since this thread has been a wealth of a variety of issues with the air ride system, I guess i'll give my story if it will help a few out there. I have an '04 with 103k on the dial and my compressor was running very often while driving and decided to replace the stock rear shockswith Arnotts Bilsteins. Granted, I didn't do a proper leak inspection with soapy water before replacing, I just relied on most people's experience with them going bad at around 100k. I replaced the shocks with no problem, hooked up the bypasses for the sensors and air lines. Now when the compressor kicks on, I get a hissing sound from what I believe is the right air hose connection. It doesn't leak so bad that the compressor never kicks off, but it does come right back on within about 30 seconds. I tried pressing on the connection when aired up, and the leak seems to be diminished, but is still there. I inspected the connector for dirt and cleaned very little out and the issue persists.

So, now, I have a complete tubing set on order since I doubt the new Arnott's would have a leak. Has anyone had issues with the stock tubing connectors? In all honesty, it looks like a rather weak way to attach a high pressure connector. I will update this post or post an update once I get the new tubing on (all places had to special order it, so I don't think it's a 'fast mover'). Any help would be appreciated, and I think my loud compressor needs to go next!


Dax
 
#273 ·
Well, with time on my hands, and a stubborn attitude, I ended up swapping the shocks to see if the problem followed. I tried the soapy water test to see if it was genuinely the connector or otherwise, but since they are new, the water just rolled off and wouldn't stay adhered to any suspect areas. Sure enough, the leak followed the shock movement. So, i'm in contact with Arnott about an RMA. Updates to follow.
 
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