24v relay switched by 12V, can it be done??

[HOWEY]

Hey troops, i know the procedure search before post, done that no joy.. so here goes....
The horn on my 09 aint a tootin like it should. I came across a 24v air horn compressor complete with horns and tubing and am hoping to fit it to the old girl, i also bought a bosch 24v relay thinking i would need that also.
My question is because the oem horn is supplied with 12v would this be enough and safe to switch the relay on to supply the compressor with 24v??
Any advice would be helpful and thanks again...

 

[philjafo]

A relay is an electricly operated switch and usualy rated by what voltage it takes to oprate it and how many amps the switch can handle befor it melts so your 24 volt relay takes 24 volts to open and close the switch, you need a 12 volt relay in place of the old horn to switch the 24 volts for the compressor. No 12 volts is not enough to run a 24 volt relay

 

[mistaken1]

There it is.

 

[rnd-motorsports]

You are doing just as the military or gm did for the starter relay.maybe yes it will work but at some point will stick or go bad just like the starter relay does best bet is to get the same relay as the doghead sterter relay swap uses then be happy! thats my

 

[philjafo]

You are doing just as the military or gm did for the starter relay.maybe yes it will work but at some point will stick or go bad just like the starter relay does best bet is to get the same relay as the doghead sterter relay swap uses then be happy! thats my

No starter relay fails because its 20 + years old and high amp load on a cheap relay. Relay is a switch that is moved by electromagnet a 24 volt relay needs 24 volts on the coil side to work 12 volts just won't do it

 

[mistaken1]

I guess you could buy a 12V relay (coil voltage) to control the 24V relay (coil voltage) to control the compressor (24V).

You are better off getting a relay with a 12V coil that has the power contacts rated for the load (voltage and amperage) of the compressor.

Whatever you do be sure to appropriately fuse any new wire runs from the batteries or terminal strip on the fire wall. The purpose of the fuse is to protect the insulation on the wire so you don't have any unplanned fires under the hood.