I recently bought my Mercedes A class and the waterpump that lets us water for the wipers is not working. could it be a fuse or the waterpump and roughly how much am i looking at replacing it/fixing?
Also the dashboard display is fading. cant be seen during the day at times but at night you can but can tell its fading??

 

You left out important info like your year and model.

You are not saying if you plan to fix it Yourself or have a Mechanic do it.

I don't know what year and model you have but you can shop on the internet for the parts you needs and see if they are available.

If it was Me I would sort of Hot Wire the little Windshield Washer Motor to see if the Motor was working or not.
If the Motor is working but no Water is coming out is also not uncommon for something to get inside and plug up the little passages.

 

Hi. Sorry it's a A class a160 diesel. 05 reg..
Ideally if its something small I would like to fix it myself but if it's not I would have to take to a mechanic. Just trying to find out how much would I be looking at if I went to the mechanic with the part or if I tried do it myself.
And the motor part I'm seeing online is not the actual mercedes part. Would that matter?

 

What little I know about Mercedes is for the old Modes in the 1980s.

Aftermarket non-Mercedes parts can range from junky to the same company that Makes the Parts for Mercedes.

Fortunately the Window Washer Motor is not as critical part as lets say an Engine Part.

If You live in a large City you will find that the Labor rate varies a lot from Shop to Shop.
It is going to vary even more if you look at different parts of the Country.

You best bet is to get out the Telephone Book and call a bunch of Shops that work on Imports and tell them what is wrong and see what they can guess their labor charge will be. Please note that if they supply the parts they add some cost to them.
By using the Telephone it allows you to have a lot of "Sales Resistance" so it is easy not to get pressured into having the work done.

Keeping in mind I have never seen the Car You have.
I think the first issues is to find out if it is the Windshield Washer Motor is working or not. I mentioned using a Jumper Wire and Hot Wiring the Motor to see if the Motor works or not.
If the Motor works OK that means it is something between the Motor and the Windshield Washer Switch causing the no work problem.
First trace the Wires and look for disconnected Wires and check to see if the Fuse is burned or if it has Circuit Breakers that the Circuit Breaker is not tripped to the off position.

If it turns out to be a problem inside of the Switch and the Switch is in combination with other Components like the Turn Signal it could get expensive because part of the Steering Colum Cover is likely to need to come off.
If you attempt to do this Yourself you should have a Service Manual that details what to do and it will tell you where the Components are before you start.
The normal Haynes and Chilton Manuals seem to fall short in this area. If you live in a Big City Your Main Library may have the big Thick Import Car Manuals and there may be info there.

If it turns out to be the Window Washer Motor is no good I think you would be able to change that Yourself.

If the Motor is working but no Water is coming out something is plugged up or disconnected.