fuel pump relay issue
You must investigate the the underside of the fuse/relay module to check for wire damage.
Remove the three screws and full out the fuse/relay module out of the fuse box and turn it upside down onto a folded towel.
Locate the connectors MR/A wire #4 Green, P/A wire #3 Green and P/D wire #14 Blue and see if there is any damage to those wires or any other wires.
i will do that and take pics for the bottom of the fuse box and tell you the result.
if i turn the ignition on the ebox cooling fan must start and keep on working all the time?
what is the cause of this?
what is the cause of this?
I would also recommend you use the search button, top right corner, and use search terms "parking brake light on With beeping".
You can then read about the plethoria of issues that it could be and learn something more about your w163.

The E-box fan was not working, i got another used one (functional in good condition) replace it still the fuel pump relay is heating up to the max...but till this moment is not yet burned/melted.
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You may have a fuel pump that could be going bad.
Trace the wiring of the fuel pump to as close to the tank as possible & tap somewhere nearby & test the current draw. You could possibly have a current leak in the wiring itself.
There is not much on the fuel pump circuit.
Fuse, Relay, Wiring & pump itself. The fault has to be in one of those 4 components.
It could also also be a bad fuse panel. I had a 10 year history of mildly over heating relays & eventually had to replace fuse panel for some other reason. All relay heating problems went away with it.
Last edited by mihir_d; Aug 23, 2019 at 10:01 AM.



Also, you need to check is fuel pump is drawing correct amount of current...
1. Current draw at fuse panel.
2. Current draw at fuel pump.
I would check and compare those numbers.
There are only those 4 parts to the circuit...if the current is within spec, then maybe relay is bad.



