Question: Horn Relay

[Go Fleiter]

Please,

 is this circuit diagram correct?

I doubt because 2 hot terminals are not needed-  unless load capacity is an issue.

The wire gauges are shown, is their capacity the reason?

 

 

 

 

Thanks for sound answers!

Greetings from Düsseldorf!

Go

Edited March 22, 2022 by Go Fleiter

[Mark D]

Consider the relay as a remote switch that is actuated by a low amperage 16ga wired switch (the horn ring). The second 12ga is the side of the relay that feeds power directly to the horns when the 16ga side of the switch is energized.

 

hope that helps. 

[DonaldSmith]

You might want the signal circuit (16 gauge, grounded at the steering wheel) to be controlled by the ignition switch as noted (IGN or ACC), so that kids in the car cannot play with the horn.   

Then you might want the power for the horn (10 gauge, noted as from the common connection at the starter solenoid) to bypass the ignition switch, because of its heavy current.   

Edited March 22, 2022 by DonaldSmith
typo, clarifications

[dpollo]

looks correct to me.  It is simply a relay for the horn and a junction point for the ignition circuit.

[Go Fleiter]

Thank You all!

regarding Ingnition lock switch:

Is the ACC terminal always ON or only with ignition key in position ON ?

So, is ACC either identical to AM or IGN Terminals?

[DonaldSmith]

The ignition switch on my 47 DeSoto has a long post which connects numerous always-live accessories with an always-live source. 

 

Turning the key counterclockwise powers the Accessories post, for stuff to be live when the ignition is not live (Such as the radio. and maybe the horn.)  

 

Turning the ley clockwise from the off position powers the coil as well as those items powered in the Accessory position.

 

I have a separate button to power the starter.  If I wired it right, the starter will work only with the key in the Ignition position.  

 

[Kilgore47]

Leave the horn hot with the key off.  It's for emergencies.  In the late 50's Mom went to the store and left us three kids in the car while she ran inside.  A couple of punks came along and jumped in the car to steel it.  We started honking the horn and they ran.  

[DonaldSmith]

The official shop-manual wiring diagram for the DeSoto S-11 (post-war) shows the horn relay powered off the ACC post, and the hot side of the relay connected to the solenoid post where the battery cable is connected.   But we have the option of keeping the horn relay hot.

[Sniper]

When I rewired my 51 I wired the horn to be hot all the time.  One day a flipped the driver's seat forward to put groceries in the back and the seat hit the horn button.

 

I jumped.  Those 6v horns are very loud when fed 12v, lol.

[greg g]

The acc post is hot with the key in run position.  It is als9hot when turned counter clockwise one click.  This enables items like fan, radio horn to be on going down the road with ignition on.  The counter-clockwise position allows radio, courtesy lights and other add on accessories ( spot light fog lights etc) to be on with ign off.  So while you are parked, listening to the radio, spotting deer,, you aren't cooking points and coil.  As far as the horn  either one is up to you.

[dpollo]

On the key start switches, the ACC terminal is de energized when the key is turned to Start.

If you connect the ignition to this terminal, it makes the engine almost impossible to start in the usual manner.

I got a really good deal on a 54 Plymouth which had been wired this way.  $10.     

[Go Fleiter]

I have installed a new ignition switch.

Bernbaum´s informed me, that they couldn´t provide the original 1951 variety. Slight rewiring would be necessary.

 

Everythig fitted well, but because of a different layout of the terminals, both wires leading to the "All Weather Comfort" resulted too tight to ignore it. I had both wires extended because I didn´t want to take out the heating controls as well.

For purists: the IGN terminal has no armour. I have never understood its sense in a car with a hood without a theft-proof lock.

 

I got a beautiful piece of US craftsmanship.

 

And well, the function is as described here earlier: I never realised that my old switch even had a left  "garage" position too!

 

Hope my sketch is correct!

Greetings from Düsseldorf!

Go