2004 e500 sputtered and then died the other day.he day before this, I had unfortunately run my tank to almost completely empty. Car cranks but will not start.
Will start on starter fluid into intake however.

1) First thought was relay. I pulled the relay, and jumped to terminals on right side, as indicated on web. No start.

2) Checked 20amp - fuse is good

3) Tried to test voltage across the two relay terminals I jumped previously. No voltage. I tried testing voltage across two contact points of various fuses. That seems to come up no voltage as well.

is it possible that I somehow lost voltage to the entire rear fuse / relay block? Is there something (fusible link / relay, fuse) that feeds power to the rear fuse block?

Is it possible that running it almost empty could clog my filter to starve motor of fuel, even if it were running perfectly before it happened?

Ran MB diagnostics. I came up with a MAF hot film code, but when cleared, it did not come back. Additionally, I unplugged maf, and car still does not start.

Help please.

Do you have a take pressure test off on the engine [picture] , for fuel rail pressure? You need to take a pressure test on it . If you ran it dry it may have damaged the pump in the tank. It needs fuel to cool it down. Can you get at the conector for the pumps it may be under the back seat See pictures .

The relay for your fuel pump is in the trumk .Did you know about that?
Relay is the very bottom one on the right .The fuse is no 20 yellow on the left Let me know how you get on checking them. This is if you did not know about them ..

Thanks for the replies guys.It seems almost as if neither of you read my post.

As I said in my original post, I know where the relay and the fuse are. I checked both of them. fuse is fine. If the car will start on starter fluid, then it obviously is not getting fuel pressure, and no real reason to test the fuel pressure at this point.

Also like I said in my original post, and the whole point of the thread, is that there is no power to the entire fuel block. I know this because I used a multimeter across the two contact points of various fuses in the block.

Right now looking at the SAM modual next to the battery .But may be in another location , but you should know its hiding place. In side is a fusable link that blows . But will have had reason to do so .One is jump starting the car . Other is removing items with ingnition on .Best thing you can do is go to YouTube videos Put in this How to fix no power no start on most Mercedes -Benz Diy...
Thats how i find out most things to help you guys .It may take me some time, but i have more than enough to spare ..Please let us know

Check rear pre-fuse block by the spare tire. Fuse 79 (200A) provides power to the rear SAM (plug 3, pin 2). It should be a 3-pin connector with just one red wire entering the plug. Ground point is in front of the SAM on the arch over the wheel.

If you can get it on a diagnostic system, do so. It is always possible the rear SAM failed.

Mercedes documentation specifically calls for the key to be out of the ignition when removing/installing the battery or jump starting. Makes sense as the EIS is energized when the key is in the ignition. I'm not sure about keyless-go but I'll ensure I keep my key at least 6 feet away from the car just in case....

Thanks. After doing some more research, I came up with fuse 79 as well. I havent looked at it yet. will do tomorrow. I ran diagnostics, and it did not indicate SAM issue, other than several can issues as they relate to the roof control panel (overhead). I recently disconnected and removed the entire switch module for lights and sunroof. I am wondering if maybe that is what caused it. I will update thread after I check.
again, thanks for the input.

So you never checked all the fuses you said you had checked . I did say more than one fuse box. Check the video out, picture book style

Can you post a pic of the pre fuse block in trunk? I can not seem to find it near spare tire. All I see is a small connector with a 20 amp fuse in it. I will post a pic of it today

Ok so i took the trunk apart to get a good pic of the pre fuse block. Now I am pretty sure this is it. Only problem is, as you can see in the pic.... no 200 amp fuses. Only a few 5 amps, and the one large 30 amp which is the green one. It has a clear top on it that said 30 amps (as far as I could tell anyway).

Any ideas? I am not sure if my fuel pump is just bad. When I check for voltage at the fuel pump relays, i get nothing. Jumping the relay did not work either. By the way, the last pic is of the trunk driver side fuse panel. The little black relay at the very bottom is the fuel pump relay correct? I apprciate all the help guys. I just want to get it running and sell it.

Next step, check f8 (30A) @ rear prefuse box located beside battery in trunk. Review attachments.

Ok, I figured it out in the process. All the fuses are good. I was able to pull back seat and test voltage at actual pump connector. it is legit. So its the pump after all. Thanks again for all the help.


One question though that maybe someone could tell me. I noticed my air suspension in the front is completely deflated. Never had an issue with it before. Never heard pump running constantly. coiincidence I m wondering. Anyone know off hand the fuse and or relay associated with the system. Car is a 2004 e500 with amg package and panroof

Galin its a google search again . in the search box put - Mercedes E500 suspension down on the front it will be in MercedesMedic web site ..I bit of info to see if you can do it yourself .But not many side garages know much about it .