S55 AMG Alternator/ SAM/Electrical Gremlins?
 

I posted this in the AMG section, but there's not much life there, so. . .

Picked up a gem from a kid who didn't know what he had nor could he handle what it needed. It's a 2001 S55 AMG with 133k. Not new, but it's clean and I got it for a price that I couldn't argue with even though it would need repairs. Just a pre-curser to the issues, the suspension was previously converted to coils with bypass module (major plus imo as I've had to incur this expense on my CL600). Car has wires attached by driver door for Sirus radio. He has tape deck wired for iPhone integration. Aftermarket tv's wired into headrests.

When the kid brought me the car, it had an engine light on- said it needed an 02 sensor, I drove it- noticed nothing except a slight vibration in reverse only. Went to go get the cash and on the way back, it wouldn't turn over, just clicked. He said he had just replaced the battery, it had never done this before. I left him on the side off the road. Kid called me about an hour later, claimed it must have been a defective battery. He had his brother take him to auto zone, swapped it out for another and the car started right up. Engine light was out, I bought it. It ran a little rougher than it had before, but I figured that was a symptom of the 02 sensor.

Since then, I've driven it minimally as my "benz guy" has been on vacation and won't be back till next Monday. I dint want to do any damage to the catalytic if it was in fact an 02 sensor.
What I've noticed:
Acceleration is slow, but seems to be no loss of power-haven't pushed it, no highway
Shudders a bit when I'm idling at a light- feels like it may stall, but doesn't
Still vibrates in reverse
Warning for FL side marker light- light comes on when I first turn headlights on, but goes out
Warning for FL & FR standing light- not even sure what those are, but all other lights seem to work
Warning once for Right mirror turn signal- light was and is working fine

Christmas Eve we had a good amount of rain, I checked it mid afternoon for signs of water- nothing visibly wet in trunk anywhere, or in cabin. Everything felt dry. Drove it that night and received a weak start and abs light on the way back. It flashed 3 times and went out/ only when my foot was on the brake. Brakes felt normal.

Didn't drive it Christmas. A little more rain today and when I go to start it, It clicks 3-4 times but won't turn over. I went out an hour later to check menu for alternator voltage and oil level. The instrument cluster lights are there, but no other dash lights with the key in the third position (ready to start). In accessory (second position) I have dash illumination (speedometer, message center, etc.). Then that starts to fade out/come back/out/back/out completely. Turn key to third position and no lights. I turned the key back and took it out, tried to put it back it and turn it again, ignition is locked in that position, cant turn key. Try to lock it up and key fob won't lock it, lights won't blink, etc. Locked it manually.

Looked up a few things and finally called Mercedes USA and they sent a tech free of charge to jump me at around 9pm. He hooked the battery up to a charger and the car started right up. Same situation as when I bought it, engine light went out, it ran a little rough. He told me to let it run for 20-25 mins and have it looked at as soon as I could because it was running rough. He said it may be a coil, but it's not normal. The car had a vibration to it. As it came up to temperature it was running and sounding smooth and almost normal. I heard a pinging sound come from the undercarriage a few times.

The warnings for the lights cycled, so I turned them on since I had to let it run anyway. Here's where things got really weird. I turned the lights on and the radio went silent/ abs light flashed- a couple of seconds later radio has sound. I did this probably five times and same thing with the radio and the flash of abs light. First time this has happened. I turn the lights off, turn the car off and the dash is dark-it's supposed to stay illuminated, remind me to take key, etc. I go to turn key and ignition is locked again, battery dead as a doornail like it hadn't just run for 30 mins. Keyfob won't work to lock it, I locked it manually.


Any ideas, experience or theories are welcomed here. I have a few ideas, but I don't know where to start. My guy is gone for another week, so that gives me time to at least pin point the probable culprits. Saves some time and some money doing trial and error later.

Dear wada a deal!---forget your brother in law the MB expert---find someone who has a DAS diagnostic set and more important knows how to use it---the resulting quick test will eliminate all the BS guess work you want us to do on a sixteen year old beater!!

Thanks for your reply, I think. I don't have a brother in law and unfortunately I don't know anyone with a STAR or Xentry. Wasn't really asking anyone to do guess work, I was looking for experienced opinions regarding the symptoms this car is displaying.

I appreciate your opinion on what's a beater and what's not, but I wouldn't consider a s55 AMG to be a beater, 16 years old or not. A 16 year old Nissan, Toyota or Chevy maybe. However some others would consider those classics.

I'm a fan of the older and less bubbled and rounded body styles.:y

You probably have a fried SAM unit from water damage, which is a very common issue with these cars as the water drain in the engine compartment gets clogged up with leaves and water overflows into the passenger foot well and destroys the electronics. I would start by checking out the passenger foot well for any moisture and checking the SAM unit under the rear passenger seat for any signs of water damage.

My first approach would be to fully charge the battery, then check the voltage at the battery with the engine running - you should have 13.8 to 14.6 volts, or somewhere in that neighborhood. If you don't have one, you can buy a cheap multimeter for less than $10.

Thanks for your input, I was concerned with this and actually had a look at that drain before purchasing it. It was clear then, but this doesn't mean it always has been of course. Now my question is, if there were water getting in, would I be able to feel it by touching the carpet? When I felt around after a good rain everything felt dry. Checking the Sam under the rear passenger requires removal of the seat or is it located in that compartment that is part of the floor? I don't do my own work, I wish I could, but I do research and talk to people like you fine gentleman so that I can point the person who does my work in the right direction. That and so that I cant be taken advantage of by the many who love to do so to us women in the automotive industry.

Thank you, I'll look into that. I read somewhere that these cars need a lot of juice and the tech that came out to jump me last night said that the battery that's in it isn't the best battery for the car. It's a duralast from auto zone. According to the kid I bought it from, it's the battery that auto zone recommended. I cant seem to find what kind of battery is best for this car, any ideas? Is it one brand is better or a different size?

The W220 Mercedes needs a high-capacity battery in good condition for reliable operation. That being said, even a slightly undersized battery should perform better than what you are reporting.

While there are quite a few possibilities for your problems, I think that the most likely answer is that the alternator isn't charging the battery properly. The reasons for that can be a faulty alternator, poor electrical connection, etc.

Another possibility is that there is a current drain somewhere in the electrical system that is draining the battery.

I understand your reluctance to attempt your own repairs. However, one approach that you might consider is to purchase a moderately-sized automatic battery charger. This will allow you to fully charge the battery and see if the situation improves. Using the charger is not at all difficult. Open the trunk, remove the battery cover, which is a carpeted floor section at the right fender. Determine which is the positive terminal ("+", may have a red cable) and which is the negative terminal ("-", may have a black cable). Hook the red charger clip to the positive, black to the negative, and connect the charger to the wall outlet.

With a good-quality charger, there will be a built-in safety function that prevents damage if you should accidentally connect the charger backwards to the battery terminals. In addition, an automatic charger will not over-charge the battery, so that you can leave it connected for several days, ensuring that the battery will be full charged. If nothing else, this should allow you to drive the car to your mechanic, saving the expense and hassle of a tow.

This: https://www.amazon.com/Schumacher-SC...attery+charger would be a good choice.

Unfortunately, any water that enters thru the air plenum under the hood will travel under the carpet - the carpet will often not feel wet at all. You have to pull the carpet up and check in the recessed channels in the steel floor for wetness.

Removing the rear seat bottom cushion requires some (but not excessive) physical strength. If you feel up under the bottom of the corners of the seat, you should find a small handle on each side. You move the handle and slightly lift that corner, then repeat on the other side, then pull the cushion out. The SAM (Signal Acquisition Module) is the electronic box on the passenger side (in LHD - Left Hand Drive - cars). This check might well be more than you want to tackle.

Wally,
Thanks for taking the time to spell that all out for me, I really do appreciate it. I was always under the impression that if there were water intrusion, you would feel it through the carpet. In addition, the instructions for accessing the SAM are much appreciated.

I will definitely pick up the charger that you recommended and I will show your recommendations/ instructions to my tech if need be. He is away for the remainder of the week, but I was searching and I found a gentleman who was a Mercedes tech for 16 years and now works for himself and is mobile. He has a STAR and a Xentry in addition to the overall knowledge of these cars. He claims to specialize in shorts, electrical and battery draws. I have him coming out today to hook the car up and inspect hoses and connections, so I at least know what I'm looking at. Hopefully he is as good as he claims. Whether or not I will complete any work with him remains to be seen, but he does have very good reviews.

I will make sure he removes the SAM while he is here so that I can rule that out as a possibility. I'd hate to replace an alternator only to still have a problem. Although my first instinct and common sense said alternator; the obvious answer seems to never be the answer with Mercedes, at least in my experience.

I came across the list of recalls that affected this year and model and I did speak to MBUSA this morning. There was a specific recall regarding static in the trunk compartment that would ruin electrical components including the battery. This particular car was affected and the recall work was done in 2007. I will want to confirm that this isn't the current issue as well, but I doubt it.

I will let you know what he finds and I will most likely have questions or want to confirm things he has told me. Thanks again for being so helpful.

See the red battery cable ?

Attachment 363991
this runs in the floor under the carpet and water fills that trough and sloshes from the front to back of the car

the car is most likely water damaged at some point , which is why it was so cheap

Tusabes,
That's a scary probability and one I certainly hope isn't the case at all. Thank you for the image though as it gives me a better understanding of how these cars are wired and what I may be up against. If that is the case, are we talking complete re-wiring or just drying it out and possibly replacing the battery cable?

In other news: I had the tech come out yesterday and he read the voltage on the battery. It was reading at only 11 and when he raved the engine, the radio went out. He said it needs an alternator, the car isn't getting a charge at all. Kind of a duh moment, because alternator was my first instinct. I just know that with Benz, the obvious answer never seems to be the answer, so I didn't think it could be that easy. He claimed that reading the codes on a power starved car is useless because it would throw a bunch of false warnings, as all the systems are malfunctioning to some extent and the car is in priority mode.

He said that I have to start with the alternator, reprogram and reset the system, then read any codes. Any insight as to how much truth this holds?

He checked out connections and confirmed that the anti-static recall work was done properly and isn't the culprit. He checked that waffle drain and said he didn't suspect the SAM or water to be the problem. According to him, it's definitely the alternator. I would be happy with this and I'm hoping he's right, but I've seen people be wrong at my expense too many times.

Even the dealer doesn't offer new alternators, only remanufactured. In a google search, I can find them remanufactured for as little as 100 and change. Dealer wants 542 with an 80 dollar core deduction. I don't mind paying the dealer price, if it really means a difference in quality. Parts Geek is 260 something with a bosch warranty and 2 yr towing/roadside assistance. OEMercedesbenzparts.com is 420 (minus 80$) core with 12 month manufacturer warranty. Mercedesbenzpartsexpress.com is 434 (minus 80$) core with the same 12 month warranty. These are all remanufactured, not rebuilt and not used. So, what's the best way to go? The dealer?

A reman alternator will be fine.

I've seen on the older cars where a bad ground for the engine will cause a lack of charging, even with a new alternator. If you were able i'd suggest you check it out yourself, but it's more technical than what we've covered so far.

ItalianJoe, thanks for that. In regards to the alternator - are they all created equal for the most part? Do you recommend the dealer or any OEM parts supplier?

Regarding the ground for the engine, what exactly is that? Are we talking a ground wire? Not that I plan on doing so myself, but what would be the procedure for checking something like this? Too bad your'e in Florida.

Thanks in advance

It does sound like an alternator or charging problem

a $100 rebuilt alternator is fine

but like was said it may be the wiring to the alternator and not the alternator itself that's damaged

He checked the connections, I don't know how thorough he was because I'm not certain how one goes about checking connections. Is there any way to isolate and just check the alternator? Or just replace it and go from there?

I agree that the alternator should be the first attack on the problem - the car will simply not function correctly without an ample supply of electrons. :)

I also agree that a remanufactured alternator should be acceptable.

your local auto parts store like autozone or oreilly should be able to test the alternator while it's still on the car

if it tests bad replace it and go from there

You guys are always the best, truly. I've learned more about these cars here then anywhere else. The alternator is definitely bad. I'm seeing that often, its just the voltage regulator and you can easily repair and replace this. Given I don't know the history of the car though and this could have been a long standing issue, I'm just going to have the whole part replaced.

It should be in on Monday and hopefully the work can be done this day as well. If not, I will update on Tuesday with where we are.

Happy new years fellas!:cheers:

Tech flaked on me, seems to always be something with this guy. I'm not necessarily mad though, a little peeved that the 200 he collected was supposed to pay labor and now I'm going to have to have it towed to my guy anyway. In looking to buy my own alternator; as the tech insisted he get it, so that I can just have it sent to my guy. I stumbled upon a thread on the other Benz forum about an X4/10 fuse terminal. Apparently a somewhat common problem. It is responsible for supplying power to the alternator and they go bad over time I guess. Located under the passenger front footboard. I can see it in Tusabes' photo above. I just cant seem to find a part number. Any input? I'd rather experiment with the $30 part prior to attempting to replace the alternator.

Yes if that part under the passenger floor is damaged your car won't work - they get damaged because of water intrusion.

you said this car did work but just wasn't charging so I doubt this part is the problem

Best place to find one is Craigslist Search for s500 being parted out

note that if your car is water damaged then likely the rear Sam and other electronic parts are also damaged

Yea the car does start right up with a jump,or quick charge. It just seemingly runs solely off battery power, as it dies again the minute the key is turned. Maybe I mis-read, but I came across the thread and the gentleman had said he replaced the alternator and it still wasn't charging. His post talked about this X4/10 fuse block being responsible for charging. I figured it would be easier and cheaper to rule this out prior to replacing the alternator. I guess I'll stay the course of the alternator as opposed to over complicating the issue though. Hopefully the alternator will solve the issue, fully. If I am still seeing an issue with charging, just for reference, is the X4/10 fuse block the same part as the battery junction box?

Just an update: Car was picked up by my guy yesterday, tow driver put a charge on it and it rolled right over. It threw just about every light and warning, but I imagine thats the "power-starved systems" revolting. Part came in a little late today, so I'll update once alternator is changed. Hopefully it truly is just that simple. On another note, after much digging for the best prices, shipping and policies on Mercedes parts. I found fcpeuro.com. Prices were great, shipping for overnight was only 30$, best part- they offer 365 days unlimited returns and a lifetime guarantee on all their parts, as long as you own the car.

Good luck , hope it's just the alternator

Tusabes, thank you, I hope so too. Wish I could say it was done but when my guy opened the part he said it was wrong.

Not by any fault of my own or tge supplier I got it from. Im actually really confused, I searched high and low and all the fitment guides on various parts supploer sites- and I must have looked through 60 different sources. Everything from aid auto, amazon to parts geek and then some. They all said this was the one AL0766X was the correct reman Bosch alternator. I even called Bosch to confirm.

That's the part I ordered, my guy says the plug doesn't match the plug on my car. I called Bosch to reconfirm and was told agaim that this is the correct part. Mind you, I gave them the last 8 of my vin and according to them, this is the only part for my car they have listed.

My guy was working on getting the original out right around 4:30 and he closes at 5, he said he'd look into it, but the plugs dont match. Ill see what the verdict is in the morning, he said it looked like I needed AL0768X.

Im stumped, any ideas on what gives or why the vehicle wouldn't match the OE suggested part?

Tech was able to retrofit the recommended alternator. Turns out, even Bosch is unaware that this year was on a different chassis. All worked out well, I was still draining dead after he replaced the alternator. Had to track down a parasitic draw. Apparently someone had not so professionally installed wiring for some kind of amp and the tv's in the headrest were drawing at 5 volts with the car off. He disconnected the power to all the above for mentioned and told me if I wanted to have the tv's redone to take it to a really good stereo place. Not really a necessity for me though, might just replace headrests and have them ripped out. We'll see, I do have kids, so. . .

Starting new thread to troubleshoot original issues I purchased it with, CEL, Rough Idle, Vibration in Reverse.