Maj. Dundee

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.

Maj. Dundee

Then while you have the fuse/relay module out, locate the ebox cooling fan. Turn on the ignition and feel with you hand if it is working.

carlos.kassis

thank you for the great help and support.
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?

Maj. Dundee

Correct.

carlos.kassis

One more problem i have in my ML 98, sometimes while driving, all of a sudden my parking brakelights turned on as well as a beeping sound while the brake was not engaged. The beeping sound only goes-on when the car is in motion, but when I stop the beeping stops but the lights stay on, and the car stay on the first gear while the light is on, the light indicator goes off after restarting the car.
what is the cause of this?

khomer2

Best to have any saved codes read with a good scanner before second guessing (and throwing parts at the problem).

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.

carlos.kassis

i dismantled and checked the fuse/relay module and no bad connections were found, nor any damage or melting traces in it.
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.

carlos.kassis

any one knows the exact cause and what is the solution of fuel pump relay heat?

carlos.kassis

i am reading many articles but no conclusions for this problem

mihir_d

You have some electrical issue. I think, you will have to test how much current, your fuel pump is drawing.

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.

carlos.kassis

Mihir_d
i just replaced the fuel pump the last week and replace the box fan. still having the same problem of relay heating up.

mihir_d

It could be something in the wiring between the fuse panel and the fuel pump. I am not an electrical expert, but that is what I would test next...
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.