wishdiver

OK I seem to be hitting a dead end here and need some help. About a week ago I was driving my 2003 CL55 and my display showed the red system not charging message. I took the car home and that weekend put on a volt meter and saw that the alternator was not charging (Tested at the battery). I went ahead and ordered a new bosch alternator (don’t ask I know I should have just gotten the voltage regulator). While I was waiting for it to arrive I decided that it was time to change the battery as well so I put in a new battery.
Now that everything is in (New belts and all) guess what? Nothing has changed!! The voltage meter is just like before. The only thing that has changed is the balance on my AMEX.

I really need some help here. The closest stealer is one hour away and I really do not want to deal with them.

Thanks
Rich

wishdiver

Well I just got back from the garage trying to figure this out. I jacked her back up and took out the multi meter to hopefully close in on the problem. I found that the battery is at 12v and the battery lead off the starter is reading 12v. Now here is where it gets interesting the battery lead off of the alternator shows 0v with the car off and only 5v-6v with the car running. I also tested the blue Lead off the back of the alternator (it is the single blue wire with a plug) and it shows 12v with the car powered on.

At this point I am at a completely lost……Could it be a bad alternator? Is it possible that bosch sold me a bad one? Anything is possible but I have to believe it is something else.

If anyone wants to chime in here I would appreciate it.

wishdiver

Well it looks like I figured it out! After all the money I spent it was finally diagnosed by justanswer.com. Never heard of them before but some guy (a Bosch tech named eurotec) diagnosed the problem and gave me the diagrams on fixing it. All in all it came down to the X4/10 fuse block in the passenger footwell. Looking around online it looks like all this will come down to a $30 part. Oh well live and learn........

jaan007

Hi Rich,

I seem to have the same problem with my Cl55 alternator not charging, I went to the Merc dealer to order the x4/10 fuse but was told that they cannot find it with that name they would need the part no; (have got the part no) I have seen the image of the x4/10 fuse sent to you by justanswer.com however it is not very clear, can you tell me if this fuse is under the bonnet or inside the car under the foot? And you also mention that you bought this part online can you send me the link for the site.
Jaan.moshref@hotmail.co.uk

Many Thanks
Jaan

Jud Chapin

Not to make you feel worse, but what I've learned over the 50 years of DIY work is to determine the problem BEFORE buying parts, especially when the parts are very expensive. I'm sure there is an AutoZone, Advance Auto or other parts house near you that would have been happy to test your old alternator for free. Anyway, I'm glad you got it fixed.

burrell1085

i have replaced the alternator the battery this x4/10 fuse box and bought all data it did not fix the problem and no one has an aster any advise

burrell1085

im also told it may also be the main control fuse box under the rear passenger seat

ctravis595

dont feel bad, i too replaced my alternator thinking it was the issue. only to have someone tell me there's a big pre fuse underneath passenger carpeting and voila my issues disappeared. if you check on the benzforums there's a post labeling the "hidden fuses" and i helped describe how to access these fuses

calgarycl55amg

Did you figure out the problem Yet? I'm interested to know . I'm having some electrical problems with my 03 cl55.

just got the alternator rebuilt with new own regulator. Replaced the battery twice.

Still have electrical issue but now I get a charge battery red light still After the car has been driven for a bit. Doesn't not seem to happen in the mornings. usually after being warmed up and driven. I did change my rad fan a little while ago.

you guys think my x4/10 could be the culprit?

calgarycl55amg

Did you figure out the problem Yet? I'm interested to know . I'm having some electrical problems with my 03 cl55.

just got the alternator rebuilt with new own regulator. Replaced the battery twice.

Still have electrical issue but now I get a charge battery red light still After the car has been driven for a bit. Doesn't seem to happen in the mornings. usually after being warmed up and driven. I did change my rad fan a little while ago.

All the gauges go out If I start the car after its warm but the engine still runs. it wont shift out of first or second gear when this happens. I parked the car right after that. Don't want to drive this car until I get this figured out.

you guys think my x4/10 could be the culprit?

mgomez137

Hello all! I recently ran into this problem where my battery was dying and not being charged. I took my battery in for testing and it tested ok so I had it recharged. After driving for about 30 minutes my car died and the battery was discharged again. I took it to a local mechanic, ( I was vacationing in California for the weekend when my car decided to act up) and he noted that the generator ( alternator) was bad. I found a re manufactured one from an alternator shop slapped it on the car. I also recharged the battery. Again after about 30 minutes of driving, the car died again. 😩. I ended up having the car towed to Phoenix AZ. The bill sucked!!! Anyhow, I did some research and all pointed to the x4/10 unit under the passenger carpeting in the foot board. I ordered a new one and while waiting for it to arrive I decided to dissect my exiting unit. Inside there are 3 bolt down fuses, two rated at 150 amps and one rated at 60 amps along with a capacitor looking thing. The smaller of the two 150 amp fuses was the culprit in my case, it was blown.

You can't identify it visually but checking it with my volt meter there was no continuity. I replaced it with a mini ANL 150 amp fuse and voila!!!!!! All systems were back on and the car was charging as usual. I left this fuse in as a temporary measure, once I received the new x4/10 unit that I had ordered I replaced all the inserts of the old with those of the new. ( I did this because getting the back plate of the x4/10 unit to disattach from the vehicle was more work than simply replacing the parts.)

To open the unit there are four tabs that need to be unclipped, the top piece to the unit will then lift off. Refer to the photos for their location. Once you have removed the top cover you will see the fuses. The smaller 150 amp fuse was blown in my case. Looking at the diagrams in WIS, it looks like this fuse is responsible for multiple items in the car. ( Power controls of front passenger seat, power controls on passenger door, power window passenger door, A/C blower motor, cooling fan, driver side low beam, generator, starter.)

biker349

great info. thanks

lukegreen

Ok I own a 94 c220 Benz.I had the same problem.I lost charge to my battery.I replaced altenator.Still no charge.I replaced battery still no charge.I towed it to mercedes in hilton head.it turns out my overload relay went bad.There is no charge for it but I costed me about $250 towing round trip.What he told me was nine out of ten times if your car is doing the same thing,it is this.Dont assume this solves your problem since all mercedes are different.But if I can save you a ton of money,Believe me I searched the internet,this information was not on here.Then Im more than glad to make this world alittle easier for everyone.SO be it! The Overload relay is under the hood to the left passenger side in the back ther is a little cover about a foot by foot,Open that up and look inside.Inside there youll see a clear plastic cover and inside the clear plastic cover there is a green fuse?anyway theres a fuse in there.If the fuse is good,the overload relay went bad.Remember 9 outta 10 times this should help you.The parts cheap so it should get you back on the road,On other models,I would also try this same thing.Check it and replace it if you already tried everything else.If you had to im sure you could figure out a way to test the relay and verify its no good Your a happy person! I will keep posting as I learn the problems with mercedes.I love my mercedes and I know you guys doo too!What an amazing work of art these really are.

CLK500 TWINS

Hey, I'm having a very similar set of issues and I was abut to replace alternator when I stumbled upon your post on another forum. Is this the battery junction box? Do you have a part number? I'd rather replace these before attempting the alternator

tusabes

did you take the car to a local auto parts store that can test the alternator while it's still on the car ? Do that test first

if you have problems with the power junction box under the passenger floor get one on eBay


note however that if you notice rust and damage on the old one it's likely the car suffered water Danage and may have more extensive problems

CLK500 TWINS

tusabes,
I cant move the car to have them test it. As stated on my thread, I had it diagnosed as an alternator by the mobile mercedes tech. It seems likely and almost obvious that it was. I just wasn't overly confident in him and being that he flaked on doing the work and my guy will be back tomorrow. I was looking to buy the alternator when I found this topic and started wondering about the probability of it being this as opposed to the alternator itself.

Johnizzosl500

Hi i own a sl500 2004 (r230) and have had issues when i leave my car for more then a few days untouched the right side of the car drops, Upon getting in to it says car too low but that didn't bother me much until my inspection sticker expired and i couldn't park the car on the street when i went to get my inspection sticker i was told my car failed do to some computers not being able to be communicate with the tester fine. I was told i needed to change my starter battery, so i went and got my battery and replaced it. After replacement i all of a sudden got a red battery on the dash that says visit workshop not sure what to do anymore called the dealer and they told me its the battery control unit witch cost $800 just for the part and god knows how much to install from MB. After hearing that answer i told them i never had that light before not sure why it would come up now they had no idea and it doesn't make much sense to me considering the battery i put in is new .
PLEASE HELP !!!

Jayshhhh

ctravis595

i replaced the fuses and the "lid" of the x4/10 junction box, as i also had trouble removing the bottom "tray" of the junction box. replace the fuse links and lid and everything should be fine

Jimmy Dallas Tx

So I got this car and I replaced everything intake manifold alternator spark plugs and 2 voltage regulators from fcp web site because everywhere I read said go with best. And nothing still battery light and no ambient no coolant no wiper fluid no fan working. NEED HELP ASAP. Please and thank you. Using my snap on tool to scan codes.

Xchekker94

I know this is an ancient thread. Since I need advice I thought I'd take a chance. I have a blown fuse in the x4/10 box. It's the top fuse. The lower 200a fuse is easily removable. However the top two fuses I'm unable to release because the right side of the fuses are under a metal plate that I cannot figure out how to release. I also can't figure how the entire box releases from the passenger footwell of the car. I would be very grateful for any help with these questions.

Xchekker94

Do you have a part number for the junction box? Do you know how to release the junction box from the passenger footwell?

ctravis595

the prefuse box is unbolted from underneath the car. Make sure battery is disconnected first or you’ll see some sparks flying