horn has stopped working

Did you check the fuse ?

Yes, its a relay, not sure how to check it

The only way to check a relay is with a volt meter and then you would need a diagram of what pins to touch to see if it is working so the best thing to do is remove a relay from fuse box the same as that one and try it or buy a new relay.

Thx i will try that.

Well, i switched out relay and still no horn,all though the horn will sound when i set the alarm off, just no sound when u push on horn in steering wheel

The relay you switched out are you sure that is the relay for the horn. Do you have a owners manual ? That will let you know exactly where the fuse and relay are located in the fuse box. If not Google owners manual and year , make and model of your vehicle and it will take you to a site that will show you the owners manual.

Yes i chkd the owners manual first. Im thinking now it may be a short...now working..ill have it chkd for a short. Thanks

Horn button maybe sticking spray with a little WD40 around the horn button that will allow the WD40 to penetrate and in stick button if that is the problem.

Penetrate in and unstick the button.

Thx

Mitsubishi diamante horn not working