Ok, I've had problems in my Dodge and now the Merc, after costing me $250 for a new battery two days ago and $900 for lights a few months ago, it's starting to give me a new problem, and a big one at that (sounds big).

Today in the morning, I shut the car off, and there was a big noise coming from the front passenger side of the engine, far front. I did a lot of research on here, and sure enough, it seems like the airmatic pump/relay. Now, the car is not low or anything, and can still drive (although I only drove it once for a bit), and this only started a day after a new battery was installed, in other words, today, which makes me wonder.

In any case, if this is ONLY to raise the car up and down when driving over puddles etc., then I don't care, and I'm just wondering where the fuse is for this particular motor so that I can just disconnect it and be done with it, I only used it like 4 times in the years since I got the car. Or can I just disconnect the pump that is making the noise, and if so, where is that? And if the fuse, where is the fuse for that (I had to disconnect the battery of course because the pump wouldn't stop and that would drain my battery completely)

I know there are threads on here about this, but I read them all and none have a diagram of the fuse or anything, and none were specifically this problem. Before I have to go to the dealer, are my options above viable? I did talk to the dealer and he said the relay is the culprit (stickiness or something) and it happens after replacing battery (this is ridiculous).

Anyway, please help, my car is a 2006 S430 (W220) 4Matic.

Thank you very much.

PS. If the above solution is not a solution at all, and the airmatic system is all connected to the ride etc., then can I just swap the faulty sticky relay myself? I know the dealer will charge me an arm and a leg, I learned that the hard way last time, and I read around here that it is a rather simple procedure, and that the part itself (the relay) is also not expensive. So, if you could point me to that (diagram to where the relay is, what it looks like, how to replace it and where to get it, locally or on the internet (I live in Toronto, ON, Canada), that would be great.

 

The airmatic is required at all Times, if you just pull the relay eventually your car will sag so low you won't be able to drive it because it will not be able to refill

The relay is a very simple part you can replace yourself . I don't have the schematic but hopefully someone else can link it for you

Do not reconnect your Battery until you have a good relay otherwise the expensive pump will burn itself out from continuous running

 

Thank you very much. Just to make sure, since my S430 is the 2006, it should have the Hella relay correct? I found lots online, the multi-purpose relay for fuel, air, all kinds of stuff, that is the one right? Anyway, I need to find one in a local parts store since I need this done right away, I can't afford to order and wait around.

Please, if someone could just show me where this relay is in the car so that I can pop it out and pop the new one in once I have it, tomorrow hopefully.

Thanx in advance.

These are the three that show up, I'm guessing it's the middle one HEL1821545 (only one that says anything about air pumps etc.), but please let me know which is the correct one, all are multi-purpose, Hella relays for exactly my car:

http://www.autopartsway.ca/PartList..../pagenum1/tabS

 

There are many different hella relays and most local auto parts stores won't have it. You'll need to get it from a dealer or an online auto parts website with speciality mb parts

If there's a Mercedes dealer near you, just go to their parts department


They will be able to give you the exact part and if they are friendly they can even show you the schematics on which one to change

 

So here is what happened, step by step, I need advice still.

I went and got the relay in question. The guy on the phone told me it goes into the N slot (secondary air pump), but when I got there, the counter guy said O slot (air suspension). But both are identical, so it mattered not.

That being said, I went with the O slot once I got home, and removed the old relay, inserted the new one, connected the battery, and started the car. I heard the air pump going, as it does every time the car starts, and sure enough, it went off after 10-20 seconds with the car running, as it should (I imagine), PERFECT. AHA, but NOOO.. I did this three times over about 10 minutes, just to make sure, listened and every time the pump went off after 10 seconds and the car idled quietly, but after I put the cover back on the fuse box and waited a bit, started the car, well, the air pump would NOT turn off while the car was on, just kept on going and going. That being said, it's better than the original problem, it does go off about 2 seconds after the car engine is turned off.

Anyhow, after that I tried all kinds of different combinations with the O and N slots, but every time same result, and I even tried to put the two ORIGINAL relays back in, and SAME result again, pump runs while car runs, turns off 2 seconds after car turns off, ODD and CURIOUS.

Is it possible that I burned out the good new relay somehow? Should I go and get two brand new relays (like I should have to begin with) and hope for the best?

The car is not rising or falling, it's riding height all the time, so really if that pump has nothing to do with riding height, then I don't even care, let it burn out, or please tell me how to disconnect it so it makes no noise (if it's only responsible for rising the car for puddles etc., I don't care). But if this pump is responsible for the whole air suspension and I could be driving and my tires suddenly hit the tire wall, well.. you know..

So how should I proceed? Any ideas? Please help me anyway you can, with suggestions or solutions, anything will do. Why did it work the first 10 minutes and three starts, then decided not to all of a sudden (turn off after 20 seconds while car running). I just don't get it.

Thank you again.

 

No you cannot let the pump burn out you will end up with an undrivable car. airmatic is used at all times not just for puddles. if you drive without the pump your car will eventually slowly drop to the point its undrivable simce there will be no air pump to raise it. airmatic is active 100% of the time either keeping the car level or raising /lowering it.


you might have a leak in one of the airmatic lines causing the pump to keep running. its Very unlikely its a relay problem if the pump is shutting off after the car is off

Its a relay problem when the pump does not shut off after the car is off and you said that issue is fixed. If that issue is not fixed and it still won't turn off when the car is off, then yes it's possible you bought a defective relay

 

Any explanation as to why the pump turned off the first few times after 10 seconds, while the car kept running (I believe the pump should turn off right? It can't run all the time while the car is running). What could have caused it to work properly for 10 minutes and three starts, then now it keeps running while the engine is on/idling, not turning off. This makes no sense to me. So don't buy new relays then? And also, like I said, the pump does turn off, but two seconds after I turn the car off, and also, this only happened after I replaced the relay (that being said, now I put the original relays back in just to test, and it still turns off after 2 seconds of the car turning off, so I'm lost).

So, can I drive about 20km to the dealer then with the pump running continuously? If it is just a leak, I don't want to also burn out the pump, or do more damage.

Any more info would be appreciated.

Thank you.

 

Thats too long for the pump to run, its gojng to burn up after 10 minutes or so

Unplug the relay so the pump is off, then you can drive it . You have a bit of time before the suspension loses all air

 

Thank you.. One more thing, about what happened today.

I took a chance and bought two relays, brand new, and put them in this morning. Guess what, again, the motor/pump was off while the car was idling (I don't know how long it was on for because I was alone, but when I got out of the car to check and listen, it was off, while the car was idling). Wow I thought, maybe it was that, and now only the actual pressure has to be checked, no need to worry about anything.

So, I did this a few times just to make sure, with 5 mins between intervals, and all ok. But then AGAIN, after 30 minute break, I tried again, and now again the pump is running continuously while the car runs, how in the world is this possible, it just makes no sense?? Is there a chance the car is destroying the relays in a short time?

The pump still goes off right after the engine goes off (not right away, about a second or two after), but I just don't get why it would work properly (not running while the car is running) for about half an hour, after numerous starts, and then just decide, nope, I'm not going to work anymore.

So weird.

Any thoughts on this?

And regarding repairs. So, I will take it in Monday morning, and the motor is still fine I presume, but what do you think is the problem here? The pump is not working? I am not spending $1000 again for something that only costs a fraction of that.


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Eg. When I spent $900 last time, it was because my blinker wasn't working, and while I replaced it before no problem, this time it wouldn't work, and they told me I have to replace the WHOLE light assembly, when after I found out that in fact all I needed to do is fix the connectors on the blinker (a small soldering job, I even have the tools, being a computer geek and all). Thank my wits that I made them give me the old assembly back, so at least I can still use it or sell it, if it is indeed so expensive.
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Thank you for any and all information you can give me so I go to the dealer prepared (my amazing local mechanic, that charges me a third of any other's price on almost any problem, or maintenance, cannot deal with this particular problem, so there goes that, otherwise I wouldn't even be here discussing this).

 

Your motor is likely still fine if you can hear it

I have no idea why it works correctly the first 4-5 times you install a relay but then runs continuously

It is possible there's some electrical fault damaging the relays but that's something the mechanic will need to diagnose

 

my brothers 2001 s430 is doing the same like your car for the past two years and he is concerned about it,but not enouh to visit the dealer,because of the bad experiance he had with our local dealer.my best advise to you is to ask some mb owners in your town for a good mb mechanic

 

Guys, I had my Airmatic system bypassed by Strut masters last year... however the local tech did not disable the Airmatic system when he installed the Strumasters kit ... now when I start the car and every few minutes the car tries to adjust the height by turning on the Airmatic system... it's loud and is useless because my car has struts and shocks it will not know when to turn off. If I pull the relay, will the Air stop? and even better, is there anything else that runs on the same relay ( will anything else stop working if I pull the relay?) I'll find out in a couple hours... wish me luck!