stuck on relay for horn

Hi All, I've spent hours going through the relay forum and haven't found the answer to my problem. I'm trying to install a second horn in my vehicle that is actuated by a push-button switch. The diagram depicted in the link is what I'm working toward. However, I'm now testing my wiring on the bench and no joy! When I connect the horn directly to the battery, it works. When I connect the horn directly to battery and switch, it works. However, I can't get the horn/switch to work when wired to the relay. The drawing below is exactly what I have now. The switch (push button) has two posts. I'm assuming one is positive and one is negative, but I'm wondering if one should be connected to 86 in the relay and the other directly to the positive post of the battery? I'm stuck! Any help is appreciated. Once I figure this out, on to installation. Thanks. 2013 Subaru Outback Limited

2005 Toyota Sequoia

I should have mentioned that I've two relays. One with 87a as pictured and one with just four posts.2013 Subaru Outback Limited

2005 Toyota Sequoia

Change terminal 85 from ground to 12V+. the12volt • Support the12volt.com

Or this way BTW a standard on off switch unless it has built in LED illumination will have neither POS OR NEG polarity, it simply completes the circuit. AS in your description grounding may be done at any good grounding point:- horn_switch.png Note; using ground to switch is the safest method.

the12volt wrote: Change terminal 85 from ground to 12V+.

That works! Thanks.2013 Subaru Outback Limited

2005 Toyota Sequoia

howie ll wrote: Or this way BTW a standard on off switch unless it has built in LED illumination will have neither POS OR NEG polarity, it simply completes the circuit. AS in your description grounding may be done at any good grounding point:- horn_switch.png Note; using ground to switch is the safest method.

No LED. Thanks for the diagram. I'm still a little confused as to your recommendation. Are you suggesting, as 12Volt did, to connect 85 to +12V and ground the momentary switch? If this is correct, the relay itself doesn't need to be grounded? Thanks!2013 Subaru Outback Limited

2005 Toyota Sequoia

I'm suggesting an alternative to the wise administrator because a ground switching terminal is inherently safer in case of shorts etc. That's why off the top of my head BMW apart, ALL car manufacturers use the circuit I posted. The relay isn't directly grounded the switch does that to complete the circuit. The relay is fed a constant live (86 side of the coil). Using the switch completes the circuit grounding 85 and actuating the relay. P.S. Your first post, 87a on the other relay isn't used in this circuit.

Ditto. It also suits single-wire & slip-ring steering wheel grounding switches.

howie ll wrote: I'm suggesting an alternative to the wise administrator because a ground switching terminal is inherently safer in case of shorts etc. That's why off the top of my head BMW apart, ALL car manufacturers use the circuit I posted. The relay isn't directly grounded the switch does that to complete the circuit. The relay is fed a constant live (86 side of the coil). Using the switch completes the circuit grounding 85 and actuating the relay. P.S. Your first post, 87a on the other relay isn't used in this circuit.

I'm looking for the safest way to do this. Does this updated diagram accurately show your suggestions?2013 Subaru Outback Limited

2005 Toyota Sequoia

Yes, quite correct.