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MG MGF Technical - horns sounding all the time

98 vvc horns sounding all the time,i have checked bonnet switch this is ok any ideas pls?
richard

http://www.mgfcar.de/schedules/sb19.jpg

coould be anything else with the Alarm ECU circuits, or a broken MFU (multi function unit)

Recommend to disconnect the horn connectors for further investigations and prevention from annoyed neighbours.
Then check what the alarm function does. (door locks i.e.)
Dieter K.

yes dieter i have done this the alarm functions as normal with the exception of the horns (which are dissconnected}
richard

Are they silent when you pull fuse #1 ?
Of course they should, but who knows.

Could be a sticky relay inside the MFU.
http://www.mgfcar.de/MFU/dk_DCP_6864.jpg

But better wait for other chaps hints before you try to dismantle half of the car.

Anyone ??
Dieter K.

do the horns still sound if you lock the car with the key instead of the blip. this will rule out the volumetric sesor
m hambidge

lock switches, or alarm sensor, it's anyway.

The problem could be the Alarm ECU, or horn switches pulled to +ve due to worn wire isolation.
Or the MFU Relay controlled by either the switches or the alarm ECU, or sticky relay contacts itself, or mis-switched due to a broken MFU.
See the wiring diagram.
Dieter K.

This thread was discussed between 13/02/2004 and 14/02/2004

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