needed for 6v horn

Hi everyone! Can you pls. help me with my 03 Toyota Tacoma horn project. I wanted to replace the factory 12V horn with a 6V horn from an old Chevy. How can I install the 6V horns safely and properly to my Tacoma?

How much current does the 6v horn require?Kevin Pierson

Sorry I'm not sure. All I know is that the horn came from a 1954 Chevy with a Delco marking and it is a 6V horn.

Connect them in series. That means if one fails, neither work. (If one goes open, cool. If one shorts internally (unlikely?) it'll place 12V across the other, but you should hear it before it burns out.) Alternatively, probably resistors equal in value to the horn in series with each horn. EG - if the horns are 10A each, V=IR hence R=V/I - 6V/10A = 0.6 Ohm. And power is P = VI = 6V x 10A = 60W. Hence a 0.56R (Ohm) 60W resistor for each, probably as 6x 0.1R 10W in series, or 6 x 3.6R 10W in parallel. Or 3 x 0.22R 20W in series or 3x 1.8R 20W in parallel. That's for each horn. There are also voltage regulators, but boosting to their current (eg 2 x 10A = 20A) can be get tricky & expensive.

If you have 2 of them, you need to wire them in series.  This may add a little challenge, chances are there is only one wire or connection on each horn.  If that is the case, you will need to mount the first horn in the path in a manner that the case of the horn is not touching the chassis of your vehicle.  The second horn in the sequence can be chassis mounted.  Positive horn wire to the terminal or wire of the first horn.  Connect the chassis of that horn to the terminal or wire of the second horn.  Ground the chassis of the second horn to the chassis of the vehicle.

Oops - I forgot to mention that minor detail... (horn body grounded.) Yet again Sir Idiot, well done. BTW: +ve or -ve ground should not matter since car horns are non-polar (any exceptions - excluding air horns and modern annunciators etc?)

Yes I have 2 horns. I'll try to wire them as mentioned above. Will report the results tomorrow.

Both horns work fine when I connected them in series but I don't like how they sound, it's NOT loud. So, I tried wiring them (NOT in series)with a relay. It worked perfectly for maybe 10 honks then the 15A fuse on the power wire of my harness blew up. Will a 30A fuse instead of 15A solve this?

I would not connect a 6 volt horn to a 12 volt supply.

For now I'm just going to experiment on these old horns. I put 20A fuse on the power wire of harness. I hope this will last a bit longer than the 15A ones haha.