Car horn Going Off at 4.30am! HELP

**TheRookieGB** · 27th October 2009, 22:43

Hi All (first post)

History:

Vestra C - 2002 52reg Model LS Silver

42k Miles.

Problem:

Horn went off at 4.30am on Monday Morning. No flashing lights, no Flashing dash nothing just the horn. One continous Front horn blast. (not the the rear power sounder, beep, beep , beep)

Stopped after around 1 minute and then went off again 15 mins later. By this time I have got in the car, started the car, locked the doors, pressed all the buttons etc. Car horn still going!!!

Had to go inside to find spanners to remove battery, done this all ok.

Left car 1 day and then on Tuesday am took to main dealer, they charged me £45 for a techtest which came up with 13 old errors, all cleared and no present error. BUT they seemed to think it may be the CIM unit and want me to replace it for £395!!!
They reset the CIM and updated it and stated that the HORN hadn't gone off since.

I now have informed my neighbours (cul-de-sack) that I have to leave it to see if it does it again.

My query is that on the tuesday morning when I replaced the battery to take it to the garage the horn went off staright away. I tried everything at 8.00am to stop it only to find that pushing the steering wheel horn stopped the horn straight away.

I'm now living a nail biting few days and hours incase it goes off again.

My question is: Do I spend £400 on a new unit or is it something else like a loose or bad switch on the steering wheel or bad earth. If so how do I test it. The main dealers are a con and I am a bit lost.

Any body else had this and cured it?

Here's hoping that the reset cleared the error. I fear the worse though.

Please reply if you have any ideas.

Cheers All

**nigec** · 27th October 2009, 23:46

Bet your neighbours have a few ideas

**TheRookieGB** · 29th October 2009, 00:38

Thats for that!

I have told the neighbours.

Horn went off for 5 seconds tonight, I have pulled the fuse (20A)

Will have to replace each time I drive it as I think its illegall to drive without it.

Any fixes for this or things to look for other than the CIM unit? Please help!

**mark_647** · 29th October 2009, 00:41

Sorry I cant help mate. Will any fault codes for this sort of thing be displayed ?

**TheRookieGB** · 29th October 2009, 00:51

Nothing on the tech test.

Only 13 old error codes that were wiped clean.

They think its the CIM £400. They maybe right but its a big cost for a £1700 trade in vectra!!!

Especially if its just a loose wire!

**mark_647** · 29th October 2009, 01:02

Ouch. See what you mean

Have you checked one of the ultrasonic sensors are not playing up ?

Im not too well up on these alarms unfortunately. Hope it works out ok tho !

**TheRookieGB** · 29th October 2009, 01:11

All advice is good advice. Please can you point me to a website or give me some points where to look and how to test?

Were is the car horn earth?

Now off to bed as its 12.10am here.

Will look in morning for any help.

Many thanks to all replies