horn relay??

[claybill]

horn relay....what does it do, in basic terms.?

can you work the horn without it?

bill

[Plymouthy Adams]

I would not try to wire the horn without the relay..they draw a bit of current..the relay contacts make the high current connection while the relay energizing low current coil has its circuit completed through the horn ring and thus protects the components from wear and tear associated with arcing high current connections.

[Young Ed]

Tim the 39-47 trucks are relay-less but they are also single horns not dual trumpets.

[Plymouthy Adams]

I'll give you that and pull my recommendation completely based on the fact I assumed the man had a car as the question was here and not on the truck side of the forum..for the record though, first Plymouth horn relay was on the 41 model..

[Young Ed]

Well Bill does have cars. Only reason I mentioned the single horn thing is his street rod has who knows what. Bill what are you trying to install on what car?

[desoto1939]

I just looked in my autloite parts catalog and the 1938 plymouth cars used horn rely HR4101 1938-39

Hrc4001 1940- 1942

HRL4001 1942-48

Dodge trucks TC series 1939 used the HR4101

If you need to know which horn rely to use I can provide this information from 1938 -1951 for Dodge, Dodge truck, Chrylser, Ply and Desoto

Rich Hartung

Desoto1939@aol.com

[Plymouthy Adams]

my factory Plymouth service manual shows all schematics from 1935 to 1941 and the 41 is the only schematic with the relay shown...not to argue only to express what is shown on the drawings..lord knows how many times we come across differences between various books..

Edited June 10, 2010 by Tim Adams

[Young Ed]

Interesting. I wonder if it was optional based. I believe the pilot house trucks came with a horn relay when they had the optional dual horns. Someone jump in if I'm not remembering that correctly.

[Ken Bartz]

Bill,

I have a horn relay from a 1940 Plymouth.

[Plymouthy Adams]

Bill,

I have a horn relay from a 1940 Plymouth.

UP FOR SALE factory book, all schematics, wrong but included anyway...lol

[Merle Coggins]

Interesting. I wonder if it was optional based. I believe the pilot house trucks came with a horn relay when they had the optional dual horns. Someone jump in if I'm not remembering that correctly.

You are correct

[desoto1939]

The autloite book shows that the 38 P5P6 had dual horns

the 1941 P11 only shows as have single horn as one option and then dual horns also

from 42-51 all then had dula horns

I have scanned in the info from the autolite electircal catalog for all of you guys that might want this info.

Rich hartung

Desoto1939@aol.com

Autolite electical ply horns 1.PDF

Autolite electical ply horns 2.PDF

Edited June 10, 2010 by desoto1939

[desoto1939]

Attached are the horn rely pictures and info

Autolite electical ply horns 3a.PDF

[P-12 Tommy]

Rich, Thanks for the info. It's good to have. BTW......my P-12 has dual trumpets. They're so loud it scares the crap outta people.

Tom

[claybill]

horn relay...I really just wanted to know ..WHAT DOES IT DO..?

in this car i have a 12v-v8. it is a 41 coupe but there is NO option to use the horn ring blower with the wire thru the steering rod to the relay etc....

i will have to mount a horn button somewhere.../ the horns will mount high on the fire wall.

are horn relays 6v or 12 v sensitive.? (they probably are)

bill

[Plymouthy Adams]

guess I am on his ignore list..was explained in my first post..

[greg g]

Simply put a relay is a low load electromagnetic switch that controls a high load circuit remotely. Think starter solenoid.

Simple answer is yes your horns can be powered straight through a heavy duty momentary switch. The relay is not as critical with 12v installations as the amperage is half that of a similar 6V load. But the longer the circuit, the heavier the wire needed.

The use of a relay shortens the route of the high load draw. battery, relay, load, as opposed to battery to switch on the dash, then back to the horn. If the hor is on the fire wall and you pick up power from closr to the switch it may not be much of a concern as the circuit is short.

Remember the stock system at the steering wheel mearly closes the ground circuit, and carries only the power needed to power the relay.

Have fun. Sure hope I not on a ignore list.

[Don Coatney]

I bought a 12 volt horn relay on the bay several years ago. It is pictured on the left in the first photo. I also bought a pair of 12 volt horns (second photo) as with my radiator moved forward and electric fan I no longer had room for the original trumpets.

[Cpt.Fred]

i have dual trumpets and relay in my 6V 1940 P-10 Deluxe. someone told me the P-9 Roadking models had single horns, but maybe they were optional all along, i have wiring diagrams with and without relays for my model from different sources.

they're so loud that they didn't want the car to get road legal in first attempt:D

[Young Ed]

Not sure about options but dads 39 roadking had a single horn

[claybill]

tim adams...not sure who you are referring to...but i re-read your posts and didnt see any reference to 6-12v situations.. where did i miss it..?

bill

[Cpt.Fred]

bill,i think tim was talking about the "what does it do" part of your question,

answered in his first post.

nothing about 6-12V, though, that's true, but i guess basically the 12V version does about the same thing,

protect your circuits when the horns draw high currents during operation.

i had a horn relay in may '69 opel running 12V.

when the fuse blew and i pushed the horn button, lights and wipers dropped dead during honking,

same thing with the ralley lights on my front bumper, which had their own relay, too.

[Plymouthy Adams]

Sorry lets see if we can make this simple, figured you would know to use the correct voltage relay...is your car 6 volt..then use a 6 volt relay if 12 use a 12 volt relay...the amperage of the relay is the current it will conduct through the contacts when loaded at that given voltage....the windings of a 6 volt relay and a 12 volt relay will not be the same impedance..the reason for the difference is that the voltage applied must engerize the coil to create a eltromagnetic field strong enough to clamp the contacts so as not to have possible chatter or create a possible risistance in the contacts generating heat, causing possible fouling and sticking of the contacts and of course to maintain proper current draw of the coil itself without heating up..excess heat will cause you yet further problems...mis-match voltages you get two extremes, excessive current or loss of clamping force..

Edited June 10, 2010 by Tim Adams

[greg g]

and just incase you need to know what goes where

[claybill]

tim...in your first post i understood everything the answer was fine and enlighteniing. i am at a real loss when talking about electricity and current/resistors etc..

...the following posts by others started concentrating on 40's and 41's whether or not etc etc.....

some times.........(*&*^%&%$$# thank you all. i am out.

bill