No pwer to fuel pump relay ??
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.
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 ..
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.
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




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




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



