Stressed out an limited time as a I start a new job the day after tmrw so Im hoping to talk this one out with one of you guys.

Finally had a day of decent weather here in the northeast US and as I have a new job coming up decided it would be good day to pull out the driver side air strut to tighten up that sway bar link i forgot to tighten all the way when I did the front end and adjust the arm for the rear height sensor as the back has been a little low and less gap than the front wheels.

After tightening and reinstallation and then backing off the ramps so I could retighten the control arm under load I kept hearing an intermittent "puff" sound. Thats when i realized i forgot to attach the airline back to the strut. Re-attached and then backed the rear wheels up onto the ramps in order to adjust the rear height sensor arm by 5mm.

After getting of THOSE ramps there was no change so I hit the RAISE CAR button and nothing happens. No air pump compressor sound nothing. STAR shows no faults and unfortunately the test released air out of the system at which point the rear wheels got so low its undrivable and sitting at my wrenching partner;s house as we speak.

I attempted to manually fill the rear struts via the rear access panel but couldn't find a way to interface.

I checked all the fuses under the hood on the passenger side, and the O relay. Connecting a battery to the relay on (i believe) 86 and 85, let me hear the relay click so i assume its functional. Its also a Hella.

What should I do here?
At this point i'm thinking pull the pump or try in car, to put power directly to the pump and see if it turns on. I don't which leads though. During my frantic googling I saw a video of a wabco intended for a w220 which appeared to have 3 leads, red, white, and black. I don't want to ruin the pump if its still good.

If it does, is there anything that can be jumped to see if in fact there is a relay problem? If there is, I'd like to know. That way I could determine if its a relay issue or a wiring issue going on.

Sorry if i said something stupid or am missing the obvious, but between my mental state, lack of food today, and the stress with a job starting i can promise you my head is swimming right now while i try to process all of this info i'm searching.

 

Like I said… Im not totally right in the head right now. Went to ARnott website to price one out just in case, and I see there is only 2 wires. ONe brown and the other red w.white tracer. Anybody know the polarity?

Also if it IS the pump, what do I need to know about a "new airline design" to make sure it works?

 

OK. might be a little more collected thinking now.

To jump the aromatic pump relay, I'm thinking 30 to 87 and probably a good idea to put something like a 40 amp fuse in the bridge just in case.

I vaguely remember that one of the other relays can be swapped with one of the others. I'll be searching around but if anyone knows which one, please post here

The big O 60amp fuse (32), would feed pin 30 on the relay socket I would think?

As far as the polarity for the pump harness, if I remember correctly, merc tends to use brown wires as ground (-) yea? So it would be safe to assume the same would follow on the pump harness.

Worst case scenario would be direct power to pump from a charged donor car battery turns the pump on, and there is power read out at the fuse and relay pins. IF at that point. A jumper wire could be ran direct to the pump from 87(?) which would indicate a broken wire somewhere.

 

The problem is now fixed, although I can't say for certain how.

I went back the next day and began by checking the fuse 32 with an MM, of course it was fine. The next step was a relay swap which yielded no results. AFter that I disco'd the pump and applied power to it directly. I used small gauge wires and also found that someone may have worked in that area previously because one of the rubber vibration dampeners and nut was missing smh. Anyway due to this i couldn't hold a good connection to the pump but i did get big spark and action. The pump however sounded unhealthy.

At that point I decided to jump 30 to 87. Of course I forgot to make a fused bridge. The pump came on strong so I decided to fill the struts which were now down with the rims inside the wheel wells. Nothing moved, so i realized I should turn the key on so the valve block would be operated. duh moment. Tried the jump again. AFter a few long moments I saw smoke. Basically my pathetically thin extra set of MM leads were overpowered, heated up, and melted. Which scared the crap out of me but I couldn't find any damage. AFter this i tried to find thicker gauge wire and failed, so I decided to try the relay again, but no response and I noticed the associated dash buttons were non responsive, no red light.

So super scared I made a huge mistake, I hooked up STAR did a full system scan, the looked at the airmatic module and ran through the initial startup actuation and THIS time got a response from the compressor. So I adjusted the car to the ride heights that I wanted it to be at as the default after adjusting the rear height sensor arm by 5mm and then inputing the default values incline angle values.

The experimented with raising and lower the vehicle, key on/off etc.

Left it there for several hours until i could get a ride back to get the vehicle and she was still fine. Put her on the road and she's been fine ever since. Sits evenly everywhere and so far no further problems, and the dash controls work.

Really odd. Idk what to think.

 

That sounds like me when I fix something. No idea how but if it works it works.

I have a question. I have access to a STAR.

1.How do I input to lower the car real low when it's shut off
2. How do I lower it slightly lower during normal operation
3. Can I have it raise up extremely high when I hit the up button so I can clear obstacles?

I tried to lower it via star, but I couldn't get any notice difference with what I changed. I had no clue. Where and what menu do I need to access? I know I'll get the do as search answer but what I've read I don't understand.