My SLS compressor is not running, at least I don't hear anything or feel anything when I put it into Off Road Mode (hood and all doors closed, window open). My air bags have not dropped, so I don't think I have leaks there.

I want to pull out the compressor and check the condition inside, see if I can overhaul it and get it running before I decide to swap out the air bags for coils.

I'm definitely a newbie at automotive electronics testing. Can I just use some test leads from the Disco car battery to "bench test" the compressor when I have it out? Also, can I use the batter to test the relay?

Thanks,

Sean.

 

If the compressor isn't kicking on at all, I'd start by checking fuses. Is a warning light illuminated?

Here is a comprehensive writeup that I've found for compressor service - I haven't used this but plan to at some point this summer: https://sixftchris.wixsite.com/lrliv...ressor-Service

 

I had the SLS warning light a few weeks ago, that has since gone out. I didn't have the codes read at the time. When I press the off road mode button, it beeps once and flashes as though it's working correctly.

I tried swapping the compressor relay (#5) with the headlight washer relay (#3), no change.

I've seen that write-up, that's one of the things that's prompting me to pull the compressor and check out the insides. If I do that, and the compress looks serviceable, I'll order the overhaul kit and try that. If it's trashed, I'll have to decide what to do next, while my Disco sits with deflated air bags in the driveway!

I'll re-check the fuses again.

 

I typically had to drive for a few minutes and then stop before my SLS would respond. It would never work if I just started the truck and pressed the button in the driveway.

 

Hmm. Mine kicks on for a few seconds on startup every time, as soon as I shut the driver door. It's pretty loud. After I shut off the truck, get out, and shut the door, I can hear it dumping air out of the springs to level out since I'm not sitting inside anymore. I haven't had problems with it rising up when I hit the button.

I'm 200lbs so not as though theres an abnormal amount of weight coming in and out.

 

I was talking about pressing the button to manually set Offroad Mode. The system will self-adjust on its own at other times.

 

So if I get to the point where I pull the compressor to clean/overhaul it, can I just attach some test leads from the battery to the compressor directly? To verify it's working and eliminate that?