Changed new car battery now car won't start , key won't turn
 

Hi all
​​my car is a 2004 w220 s500. I let the car sit a couple weeks and the battery got real weak. When I jumped the car with the old battery it would start and run fine with no issues. However when I went to restart it it has no juice to start the car again so I figured I get a new battery.

So I went out and bought a Costco interstate agm battery and installed it now I can't even turn the key in the ignition. I get dash lights and can power the trunk but that's about it. The brake pedal feels higher and stuffer than usual.

It's like something is not registering with the key or a blown fuse I don't know . The key will go in the ignition but it won't allow me to turn. The remote also does not do anything when I press the button to lock unlock car etc. Maybe there is a reprogram procedure.

Any input on how to fix. The only thing that has changed from a perfect running car to this was the swap of the Costco battery.

Any help would be appreciated

Shake the steering wheel hard left and right quickly while you try and turn the ignition on... I suspect the wheel may be locked

Also check that the battery terminals are clean ...also make sure your new battery has a decent voltage across the terminals - may have been sitting for a while or a bad battery

once it's running you'll need to reset some things ... see link

https://www.mercedesmedic.com/6980-2/

There is no steering lock on these cars.
Is the brake light lighting up when you press the brake pedal?

When you jumped it, you blew the pre-fuses under the front passenger floor. That’s why putting in the new battery didn’t help you at all.

So is it just a matter of swapping the blown fuses with good fuses? Where are the fuses located in the footwell and would you know how big they are ? Is it near the red wires where you jump the car. The Mercedes roadside did this and they used the ground in the footwell and the smaller terminal with the red wire . Come to think of it I think I heard a loud pop when he connected the leads . It's strange the car started with the older dead battery when it was boosted then shut right off. The old battery when I took it out and tested was pretty shot. Only putting out like one volt with my multi meter

The new battery is putting out like 12.5 to 12.6 but like I said the dash lights come on but I can't turn the key or put it in neutral with the shifter.

Yes they are inside the black plastic block where you jumped it . They are large fuses you can only find on Amazon or eBay not the auto parts store

once i reversed battery cables and this happened

Update

Yes T was right! The dealership blew the fuse in the pre fuse box. It was showing good with his tester but upon replacing it with a brand new one it worked and started.

However they caused a major issue when towing which I will los on a new post

Thanks for your replies

so you admit, something changed with the brakes while you were playing with the battery, before it got towed and before it went to the dealer. Why are you blaming the dealer in your other thread? You also admit you are the one who changed the battery with a Costco battery yourself. You were probably the one who blew your pre-fuse box, not the Mercedes roadside tow service. It’s time to start taking personal responsibility buddy. You screwed up your own car due to your lack of knowledge on how to perform repairs yourself, and now you’re looking for someone else to take the blame and pay your bills.

Anyone have part numbers for these? I wouldn't mind having them on hand. Every time something needs to be replaced it's a waiting game to receive parts.

there are no part numbers for the fuses because Mercedes only sells the complete distribution block with the fuses built in . They are 60 amp and 150 amp fuses . There are also other parts inside this block like resistors and capacitors which get damaged when a person jump starts their car wrong so you need to get the whole block . The part number for the fuse block is 2205460641in the pic below

https://cimg4.ibsrv.net/gimg/www.mbw...9dd6f9229e.png

Thanks for taking the time to respond with the info. I did come across the assembly while looking but wasn't sure about the individual components.

I think this the problem, chek this fuse