Fuel gauge problem

Hi all.i have a jetta mk3 cli 1.8.the car model is 1998.my problem is that the fuel gauge is working but the pump is not working (there is no supply of fuel to the fuel rails)i changed the fuel pump relay but it still does the same thing.when i connect the pump directly,it works fine

 

fault finding needed. test meter. 12v at pump? earth at pump? 12v power to relay? signal 12v getting to relay?
relay earthed? fuse ok? use a diagram and get help if you need it, we all continue to learn, no matter how old..
Jon

 

Thanks Jon.looks like i will have to bring in an auto electrician to come and have a look at it

 

Strangely my mk3 pump lost its earth supply so ran a separate one.
Would suggest getting a cheap multimeter and can test continuity to earth and voltage at plug.
Or wire a test bulb to see if got power to the tank

 

Thanks again for your advise.i did wire a light bulb to the main plug but there is no power.what i cannot figure out is how come the gauge is working but the fuel pump is not?

 

Where can i run my separate earth from?from the ignition or from any metal part of the car?

 

Any metal part of the car, or back to the earth terminal in the fusebox, its all the brown wires for earth on vw.
Can ways put your yest bulb on the +ve supply to pump and the other side to the screw that holds the access cover plate in place to check if it is earth dropped.