Horn relay

[Clive85]

Hello, I’m new to Z3 ownership and slowly working through a list of “faults” one thing I’m stuck with is the horn, only one works on one side, fuse is good, but the relay as a jumper wire on it? Any ideas why someone would do this or could this be my problem, I removed the wire to see what happens but the neither horns worked, any advice would be greatly appreciate.

 

[Delk]

86 and 30 are both power wires.
86 is powered from the ignition switch and works with 85 the horn button as a ground to activate the relay.
30 is the power for the horns fed through fuse F8. This outputs to 87 when the relay is activated to give power to the horns. They is a split in the wire to feed both the right and left horn.

The horn only works if the ignition switch is on. Found this a bit different from most of the cars I had in the past as the horn was always powered.

If the jumper wire is required you have lost one of the two power feeds. Either the one from the ignition to power the relay or the feed from the fuse to power the horns. So jumping them across will feed both from one of the power sources.

One horn not working is either down to a broken wire, connection or horn itself.

 

[Clive85]

Thanks that make sense, so I can rule out a faulty relay? I have a replacement horn so I’ll try that next