hello,I bought a 2005 sl500 at a auction, non running. Now,I put 2 new batteries on it, and is completely dead, no a single light or electrical thing works. is like it dont have batteries at all! do this sl500 have a "main fuse"?

 

There is a pre-fuse block in the rear above the battery with 7.5A, 60A and 200A fuses. I'd check all of them.They are the three pre-fuses that power every module on the car.

 

Considering that Tom shared the following Prefuse diagram with me, I'm surprised by his statement above. Yes, those three "rear" pre-fuses are critical, but there are more. The 200A rear prefuse powers the fuse/relay box behind the passenger seat. The 60A rear pre-fuse powers half of the fuse/relay box under the hood on the right side.
There is another pre-fuse block in the passenger footwell (takes an hour to get to) which powers the other half of the front right fuse/relay box, the entire front left fuse/relay box, the engine radiator fan, the interior blower motor, the SBC motor and the EIS locking system.

With the rear 200A prefuse good and all the fuses and relays good in the rear passenger side fuse/relay box (also called the passenger SAM), the rear trunk light should work, you should hear the rear vacuum pump run, and more.


Tom, thank you again for sharing this diagram with me; I still don't know where you found it.

@12master - Start in the back and tell us how far you get.

 

This is NOT a car I would buy "dead" at an auction. You have not even considered the the complex hydraulics in both the suspension and folding top.

Good luck to you sir

 

awesome! is too much to ask for the exact location? thanks for answering!

 

thanks! any picture or exact location of the f33 box? thanks for anwering!

 

I'm not afraid! lol!

 

First picture shows that it is directly behind the rear batter. On my car, I would need to remove the plastic battery support panel to access it.

2nd picture shows that the positive battery terminal splits into two big wires - one to this F33 fuse box and one to the "Battery Control Module" hidden under the carpeting.

The positive battery goes to the top post of the F33 fuse box. Start by checking for voltage there or on the 7.5A top fuse. (That might be easiest.)
Then check the two lower posts which are after their respective fuses.
If you find that voltage goes to F33, but one of the lower posts has no voltage then you have a blown fuse.
I don't know the exact trick to remove the F33 box, but you first have to disconnect all the wires going to it and then likely lift it up and out.
As I have spares of almost every fuse box and module on my car, I have included pictures of the inside front and back of the F33 fuse box. Notice you would have to remove it to access the 60A and 200A fuses in it.

Why not start checking for voltages in this fuse box and we can help you from there.

 

the big one was blown! thanks! now she starts! wow! now to find out why the front only raises, but the rear stays down!

 

thanks to members here I foiund the big fuse in the back was blown, now she starts! as a setback, only the front of the car raises , the rear stays down! well, you can not have everything! lol

 

Great start (literally and figuratively).
Now, it sounds like you have a suspension problem; these cars have a complex hydraulic suspension called "ABC".
First step is to check the fluid levels in the ABC reservoir and you might as well check the PS reservoir too, especially if you are not sure which is which. Make sure both have fluid. Left side of engine compartment; larger is the ABC.
Next , use a scanner to check for codes and tell us what they are.

 

I will! thanks for your help!

 

Correct on the fuses, since the car was completely dead I guessed it would be one of the three at the back (it was) otherwise he'd be getting something, not nothing. Must have been a hell of a short to blow the 200A.

Here's the full battery system link at https://www.benzworld.org/threads/r2...ation.2899538/

Are there any ABC messages on the dash? Do both wheels on the rear stay low? Start by removing the LHS wheel liner and checking the connections to all four valves on the valve block. You'll have a ton of stored codes in there; clear everything out and see what comes back.

 

It is possible that the car had a blown accumulator which deposited a piece of its rubber diaphragm in one of the lines. I don't think it's that common but Legit Street Cars on YouTube had the exact same fault and that was the cause.


A blocked line would definitely cause it.

Take off the inlet to the rear valve block and start up the car; if the line is blocked there will be little or no pressure. If it's clear then fluid will squirt out at high pressure.