Engine cutting out when pressing horn

Hi guys ,discovered a new fault yesterday when I hit the horn the car cuts out when released ,the car runs again can anyone point me in the right direction

Best regards Dirk

Sounds earth related to me, but check out all the horn wiring first, does your horn sound when pressed?

Yes horn works but soon as you release it the car goes again , if you hold it in for a couple of seconds the engine will cut out

Thanks for your reply, regards dirk

this is going to be a complex one to solve, from the factory the horn wiring has nothing at all to do with the ignition/fuel wiring so it sounds liek your loom is bodged/damaged.  might be a dodgy ignition switch so thats worth a look. also what car is it? does it have the high spec dual horn setup, if so is the horn relay fitted

Hello John,it's a 1989 gti cabrio mk1 ,and yes it has the dual horn had them off today clean all contacts and you can here the relay clicking fastley?

It's got a wipac immobiliser fitted ,thought it was a simple earth fault but I am gonna fix it ,you have to hold the horn in for a second or two and the car dies,but a quick blip and it's ok,

Hope you can help mate thanks for you reply

Best regards Dirk

hmm, i wonder if the alarm has a power feed from the X contact feed on the switch (this is the one which does the lights, wiper, horn etc and cuts power to these when cranking)  if so a volt drop on this wire caused by horn load could explain why it cuts out if you hold it down.

to start with i would trace the black/yellow wire from the ignition switch to see if its been cut into

Thanks John I will look at it tomorrow what you come up with makes sense I will let you know how I get on

Thanks for your reply

Best regards Dirk

I have the same issue, going to check all that is suggested today, will let you know what I find.

Dom