Technical 2009 x250 horn not working

[GrumpyOB]

Hi, the horn stopped working so I've checked the following:
Fuse ok, relay removed and checked ok.
Power in Fuse box relay terminals.
Direct 12v makes horn work.
Airbag removed and power at horn connection to airbag module.
Power before and after clock spring.
When sending power to relay from steering wiring I only have 11.5v at relay switching terminal but 12.6v at relay battery feed terminal. Should 11.5v be enough to operate relay? Trying to track where voltage loss could be. Fuse box disconnected, removed & checked but no obvious corrosion there. HELP! Getting to stage of running cables through bulkhead to separate dash mounted button

 

[rayc]

Is negative getting through the switch when horn is pressed? It is negative via the switch that operates the relay.

 

[GrumpyOB]

Is negative getting through the switch when horn is pressed? It is negative via the switch that operates the relay.

Yes, at Relay terminal goes negative. Took me a while but realised modern relays are wired like that. It's the 11.5v at the switching terminals instead of the 12.6v at live feed that's throwing me. Should 11.5v be enough to operate the relay?

 

[Communicator]

Yes, at Relay terminal goes negative. Took me a while but realised modern relays are wired like that. It's the 11.5v at the switching terminals instead of the 12.6v at live feed that's throwing me. Should 11.5v be enough to operate the relay?

In a word certainly,

 

[GrumpyOB]

In a word certainly,

I thought that too. Thus the post on here. Will have a day or two away from it, see what ideas come up on here and have another go later in the week.

 

[rayc]

Why not run a negative directly to the switching contact of the relay? Does the relay operate and the horn sound?

Can you expand on your comment "Direct 12v makes horn work". Direct 12v to where and under what circumstances e.g. horn button pressed?

 

[GrumpyOB]

Why not run a negative directly to the switching contact of the relay? Does the relay operate and the horn sound?

Can you expand on your comment "Direct 12v makes horn work". Direct 12v to where and under what circumstances e.g. horn button pressed?

If I feed 12v directly to the horn it works. I can jump the positive battery connection to the horn feed connection in the relay terminals and again the horn sounds, suggesting the wiring from the fuse/relay box is good. The earth to the relay terminal is one I haven't tried and makes sense, thanks. I'll try that Tuesday as the van is in storage away from home. I'll update this once I've tried that.

 

[GrumpyOB]

Why not run a negative directly to the switching contact of the relay? Does the relay operate and the horn sound?

Can you expand on your comment "Direct 12v makes horn work". Direct 12v to where and under what circumstances e.g. horn button pressed?

Ran negative to the relay and it switched and horn worked. Then remembered a moisture collector on dash overflowed into dash panel and spent months plus, dripping out into passenger football. Removed a few panels and liquid is still there. Will carry on looking to see if it's corroded any terminal, connectors or earths behind panels.