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Hi! I really need some help.

I've got a 2005MY 320D, which, about a month ago wouldn't start. I towed it to my local BMW workshop to have the problem identified, and after a while they told me that the pre-supply fuel pump was faulty and needed replacing. Being young and a student, naturally I ordered a pump and decided to replace it myself. Replacing the pump was done in 10 minutes, probably the easiest repair one could do. Now to the problem, the car wouldn't start anyway.

I tested both pumps by giving them 12V directly, and both pumps worked fine. Of course one of them was connected to the fuel line just to really make sure it worked, and it sprayed diesel everywhere, so no doubts there. So the problem is that the pump isn't getting any power. I've checked all the fuses and replaced every one that has something to do with the fuel system, even if they didn't look burnt. I replaced the fuel pump relay, I tried 4 different ones, so the fuses and the relay can be ruled out.

The fuel pump relay has 12V going into it, which I measured with a volt meter. Then there's the current that activates the relay, which I measured to 3.8V. I've got about a quarter tank of diesel and the battery is at 13.1V, so those aren't the problem either.

So the pump not getting power is determined. Then what could be wrong? Is the activating voltage for the pump relay supposed to be as low as 3.8V? If not, what could cause that? If it is, where between the relay and the pump could the problem be?
 

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Hi! I really need some help.

I've got a 2005MY 320D, which, about a month ago wouldn't start. I towed it to my local BMW workshop to have the problem identified, and after a while they told me that the pre-supply fuel pump was faulty and needed replacing. Being young and a student, naturally I ordered a pump and decided to replace it myself. Replacing the pump was done in 10 minutes, probably the easiest repair one could do. Now to the problem, the car wouldn't start anyway.

I tested both pumps by giving them 12V directly, and both pumps worked fine. Of course one of them was connected to the fuel line just to really make sure it worked, and it sprayed diesel everywhere, so no doubts there. So the problem is that the pump isn't getting any power. I've checked all the fuses and replaced every one that has something to do with the fuel system, even if they didn't look burnt. I replaced the fuel pump relay, I tried 4 different ones, so the fuses and the relay can be ruled out.

The fuel pump relay has 12V going into it, which I measured with a volt meter. Then there's the current that activates the relay, which I measured to 3.8V. I've got about a quarter tank of diesel and the battery is at 13.1V, so those aren't the problem either.

So the pump not getting power is determined. Then what could be wrong? Is the activating voltage for the pump relay supposed to be as low as 3.8V? If not, what could cause that? If it is, where between the relay and the pump could the problem be?
Hi! I really need some help.

I've got a 2005MY 320D, which, about a month ago wouldn't start. I towed it to my local BMW workshop to have the problem identified, and after a while they told me that the pre-supply fuel pump was faulty and needed replacing. Being young and a student, naturally I ordered a pump and decided to replace it myself. Replacing the pump was done in 10 minutes, probably the easiest repair one could do. Now to the problem, the car wouldn't start anyway.

I tested both pumps by giving them 12V directly, and both pumps worked fine. Of course one of them was connected to the fuel line just to really make sure it worked, and it sprayed diesel everywhere, so no doubts there. So the problem is that the pump isn't getting any power. I've checked all the fuses and replaced every one that has something to do with the fuel system, even if they didn't look burnt. I replaced the fuel pump relay, I tried 4 different ones, so the fuses and the relay can be ruled out.

The fuel pump relay has 12V going into it, which I measured with a volt meter. Then there's the current that activates the relay, which I measured to 3.8V. I've got about a quarter tank of diesel and the battery is at 13.1V, so those aren't the problem either.

So the pump not getting power is determined. Then what could be wrong? Is the activating voltage for the pump relay supposed to be as low as 3.8V? If not, what could cause that? If it is, where between the relay and the pump could the problem be?

hi , did you manage to find a solution. As I’m in the same position right now . I’ve run a wire straight to pump and used it with cigarett lighters to get to work and back, for about a month ,disconnected the battery and went to holiday when came back after a month car fixed for about another month yet again cutout in middle of road and now I’m back at square 1 . I want to mention that I’ve changed all fuses and the pump relay before without any success resolving the problem . Thank you
 
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