2003 Volkswagon Passat Monsoon Radio, nosound,

Have your ignition switch check or if this working have your engine starter check by a mechanic

FIRST CHECK FUSES AT THE LEFT.A 10 AMPS MINI FUSE IS RESPONSIBLE FOR THE POWER WINDOWS AND COMFORT .SECOND CHECK IF WATER IS PRESENT AT THE DRIVERS SEAT FLOOR!!IF SO TAKE OUT THE COVERS AT THE DRIVERS SIDE AND LIFT THE CARPET.UNDERNEATH U WILL FIND A BLACK BOX.INSIDE THE COMFORT CONTROL UNIT LIES !!!!HOPEFULLY WITH LITTLE WATER INSIDE.TAKE IT OUT AND CLEAN.CHECK CONTACTS AT THE CONNECTORS FOR CORROTION.

there is only some steps you have to do before you change the battery So as to avoid losing any codes (radio and anther some features for automatic doors lock when 20k/m speed,,,,) keep radio off ,all doors unlock ignition key outside your car.then replace battery .

The serpentine belt routing diagram for 2003 VW Passat V5 2.3 liter


CS = Crankshaft
F = Fan pulley
Gen = Alternator
G = Guide pulley
T = Tensioner pulley
AC = Air Conditioning
PAS = Power Assisted Steering

There is a tank under the hood with a STEERING WHEEL icon on it. DON"T OVERFILL and use only PENTOSIN

Pull the radio fuse for 10 seconds.

there are adaptors that go between antenna and radio that ipods will disrupt the signal and work that way

I have come to find out that in the 90's auto makers started installing factory amplifiers in their cars so they could use low wattage stereos in the dash. It's usually a blue wire off the stereo that runs the amp, maybe it couldve become disconnected? I also know that even if you put in an after market stereo, this wire must be hooked up or you'll get no sound from the speakers. hope this helps.

May just be the wiring of the car or maybe something is loose or became disconnected. If the radio has been removed then that's an easy problem to get. It may also be the anti-theft system. Some vehicles can be very difficult to install a stereo system or any other add-on because of the way it's wired for the anti-theft.
I have also heard that some of the Jettas had wiring problems that were hard to trace. I know someone who had one that was an early 2000 model.
Try to find out if there were any recalls about that, but I would probably just get another one installed at some place that's experienced with radio installations because they would know how to wire these thing in. Hope this helps

i would like to advice you not to do this job, the person who is doing this work must have more knowlage about mechanical mainy must know how is the timing belt fitted,
timing belt is not like altaranator belt.
find a good mechanic,
if you are intersting to do like this job easy go technical schools, .