Vw polo 1.6gti year 2000 horn not working

Fuse #40 on one model.. Look here for your year:

https://www.google.com/search?q=VW+polo&ie=utf-8&oe=utf-8#q=vw+polo+fuse+box+layout

Horn relay could be bad too.

More than likely its bulbs .

Did you check the power to the relay? and then the signal wire (ground) at the relay to see if it's being signaled? Otherwise you may have a clockspring or module problem not allowing the signal to pass through to the relay.

check your fuse first. if fuse is fine then is probably the horn relay

Hi.if the speakers is to big for the Radio it wil frey the internal amplifier of the radio

Check the top right hand mini blade fuse 7.5A .My washers stopped even though the wipers were ok.Mechanic at my local garage told me about the fuse.

alot of cars have differant placement for fuses. what you might want to do is read the owners manual or go to vw's website and find out the fuses location then you can replace it

its check engine light. have the computer scanned

your multi function switch is bad. hope this help buddy

Hi!  I believe that is the check engine light.  It means that there is some part of the engine that needs attention.  It can range from routine maintenance (a dirty filter for instance) to a serious problem.  You will have to take it to a dealer for them to diagnose the specific error using their diagnostic computer.
I'm not sure about the Polo but for several VW models the Check Engine Light goes on when the gas cap isn't on tight (there is a sensor that monitors tank pressure).  You may want to check that first.

Hope this helps.