Sound of fuel pump during glowing

Hi all,
my TD5 is not starting properly when it's cold outside but before discussing this issue I want to know if I maybe have an electrical issue in my car. During glowing, my fuel pump sounds a bit slower and interior lighting is a bit darker. Sound example (please watch the video for at least 15 seconds):



The 4 glow plugs are a year old. Does it sounds in your car similar if you have 4 functional glow plugs fitted?

Thank you in advance.
Mario

Let me add one more impression:

Sounds like your battery can’t give enough current or something,

have the battery checked and make sure the alternators is charging properly

Thanks for your answer. Battery is less than a year old, has 100AH and is specified with a cold start current of 800A. I've charged it fully before I made these videos.

Just to get sure, no one of you has this issue, correct?

Mario110 said:

Thanks for your answer. Battery is less than a year old, has 100AH and is specified with a cold start current of 800A. I've charged it fully before I made these videos.

Just to get sure, no one of you has this issue, correct?

Click to expand...

Check the earths too, the circuit must be clean and tight to work properly ...

Mario110 said:

Thanks for your answer. Battery is less than a year old, has 100AH and is specified with a cold start current of 800A. I've charged it fully before I made these videos.

Just to get sure, no one of you has this issue, correct?

Click to expand...

In which case check your earths.
As a simple test connect a jump lead from the battery negative to the engine block somewhere and see if that makes a difference - if it does your engine earths are shot

Thanks a lot. I will try it with a jump lead.

Besides of that I've another question: My earth is going from battery to chassis then to the transfere case. Is this the only earth to connect the engine? I've measured contact resistance from that point to starter case about 0,9 Ohm. Is this value good enough?

Connecting earth via a jump lead does not help much. So, between these two frequencies of sound the difference of voltage is 0,1V. Not much.

Measure voltage across the fuel pump's fuse F4, the values for Defender should be the same like for D2 if the fuse is 30A, if it's 20A recalculate based on the table or fit a 30A fuse to measure Check Td5 fuel pump HP

Thats a good idea thanks a lot. My pump has a pressure of 4bar, so I think it's ok.