12v horn relay and leaking amps

[paulwaite]

Ever since this Rally build, something has caused my battery to leak at 0.18amps. After methodically going through the wiring to eliminate leaks, it looks like it comes down to how I may have connected my horn relay. (horns are twin 12v horns)



My thoughts are that I should connect 86 on my relay to the yellow wire between the horn and switch. I think that because I have connected to the grey live feed, there may be a small current passing through the relay. (Note, I have isolated the grey wire from the brake switch to isolate any c**k up with those flimsy brake switches.



Any comment would be gratefully accepted, see my wiring below which is 12v DC.

[sime66]

I'm not particularly up on the subject but you asked; I wouldn't want to lead you from the path to righteousness, so treat this with caution. This is how I sketched it:



Your trigger circuit is from rectifier (grey) to switch (4) and ground via yellow, so grey = (86) and yellow = (85) (or the other way round; it doesn't matter). There is no current from grey until switch closes the circuit and grounds it. 85 and 86 are effectively where the terminals for the old horn were, now serving as the relay trigger.

The live is from battery to (30) and from (87) to 12v horns and ground at horns.

The loom grey is a common 12v DC supply to brake light and lighting/horn switch, but no current will pass through relay unless circuit is made on switch at (4).

I think this would work. I don't think it would allow any 'leakage' – you show grey (86) to ground (85), which would. You also show the switch on the horn circuit, not the trigger circuit, so the realy as you have it isn't really doing the correct job either.

Hope it helps; just ignore me if it doesn't.

[pxguru]

Yeah, that's going to cause a leak through the coil. You were lucky it didn't catch fire! As Sime said!

[paulwaite]

Thanks Sime and PXguru, points noted and appreciated.
All the best
Paul

[paulwaite]

Thanks chaps. Rewired to Sime's layout and all works great. No leakage and loud horns, so thanks