Horn in-op

Discuss fixes, upgrades and modifications to your M37

Moderators: Cal_Gary, T. Highway, Monkey Man, robi

Post Reply
ez8
SGT
SGT
Posts: 175
Joined: Tue Jul 11, 2017 6:37 pm

Horn in-op

Post by ez8 »

Yesterday while driving to the post office a gentleman leaving the grain elevator didn't see me and started to pull out into the street. As I cursed and swerved it occurred to me that I need to fix my horn.

How do I go about diagnosing the problem? I have a multi-meter and I understand the concepts of positive and negative, but other than that I haven't a clue what's going on.
How do I determine if my issue is the horn unit or the wiring / horn button?
ashyers
MSGT
MSGT
Posts: 845
Joined: Mon Jan 05, 2015 8:20 pm
Location: Oakland CA

Re: Horn in-op

Post by ashyers »

ez8,
Switch is in the horn button, wire goes down the column and usually gets damaged and shorts leading to a whole lot of horn. Maybe you're lucky :lol: !

First I'd hot wire the horn and see if it's working. Then I'd hook the meter to the horn's leads and see if you're getting 24v when you press the switch. That should get you started on the hunt.

If you need parts for the switch it's best to purchase the whole kit.

Andy
Cal_Gary
Moderator
Moderator
Posts: 4353
Joined: Mon Oct 22, 2007 5:51 am
Location: Draper, Utah

Re: Horn in-op

Post by Cal_Gary »

And if you go the kit route, tie a long piece of dental floss to the old horn wire before you fish it out. The floss will allow you to reverse course with the new wire right through the steering shaft :)
Gary
Cal_Gary
1954 M37 W/W
MVPA Correspondent #28500
G741.org Forum member since 2004
ez8
SGT
SGT
Posts: 175
Joined: Tue Jul 11, 2017 6:37 pm

Re: Horn in-op

Post by ez8 »

ashyers wrote:ez8,
Switch is in the horn button, wire goes down the column and usually gets damaged and shorts leading to a whole lot of horn. Maybe you're lucky :lol: !

First I'd hot wire the horn and see if it's working. Then I'd hook the meter to the horn's leads and see if you're getting 24v when you press the switch. That should get you started on the hunt.

If you need parts for the switch it's best to purchase the whole kit.

Andy
Does the engine need to be running when I do this or can I just switch the ignition on?
Cal_Gary
Moderator
Moderator
Posts: 4353
Joined: Mon Oct 22, 2007 5:51 am
Location: Draper, Utah

Re: Horn in-op

Post by Cal_Gary »

Hi ez8,
Most horns are already wired "hot" as I understand it. If yours is not, it should have current once you switch to "ON" but it is not necessary starting your rig to check.
Gary
Cal_Gary
1954 M37 W/W
MVPA Correspondent #28500
G741.org Forum member since 2004
NAM VET
1SG
1SG
Posts: 1118
Joined: Mon Aug 22, 2016 6:27 am

Re: Horn in-op

Post by NAM VET »

always "oh", as I can attest because from time to time when I am under the hood, my your grandson likes to surprise me with a push of the horn button. HC
ez8
SGT
SGT
Posts: 175
Joined: Tue Jul 11, 2017 6:37 pm

Re: Horn in-op

Post by ez8 »

Went out and hooked it up, no juice at all. No voltage, no resistance.

I can't find how it's connected to the horn button, though. Where's that connection get made?
PoW
SFC
SFC
Posts: 523
Joined: Wed Nov 14, 2007 5:48 pm
Location: Hidden Valley, AZ

Re: Horn in-op

Post by PoW »

The M37 horn has two terminals, one is always hot 24V.

The other runs thru the loom, down to a hole in the frame, then up the hollow steering column to pick up a ground when you push the button.

If no +24 at the horn, check under the dash for a bad breaker or disconnected wire.

Prince'OWeird
User avatar
m-37Bruce
1SG
1SG
Posts: 2340
Joined: Fri Oct 19, 2007 8:21 pm
Location: Midlothian,VA

Re: Horn in-op

Post by m-37Bruce »

ez8,
I wanna help, but I'm 12 volt and Painless wiring loom. My hot wire comes from the front part of my harness, always hot. The wire goes down the column, then comes out the bottom of the fitting and is sealed. I'll try and take a pic tomorrow, ok?
Bruce,

1953 M-37 w/ow

Retired Again

Keep Em Rollin'

VMVA
NAM VET
1SG
1SG
Posts: 1118
Joined: Mon Aug 22, 2016 6:27 am

Re: Horn in-op

Post by NAM VET »

it may not work with loudly with 12 volts, if you can, they putting some wires from 12 or 24 volts batteries and see if your horn works with both volts. I ended up with a horn from Hella at 24 volts, bolted right up to the hood mounts. You. get the horn button off by pushing it in and then turning it. Mine will pop off if I tap it hard, but replaced in very easily. I push and not "pop" it to sound it. Horns take a lot of amps to sound off. Hc
User avatar
m-37Bruce
1SG
1SG
Posts: 2340
Joined: Fri Oct 19, 2007 8:21 pm
Location: Midlothian,VA

Re: Horn in-op

Post by m-37Bruce »

I forgot to take the pics!! Promise tomorrow.
Bruce,

1953 M-37 w/ow

Retired Again

Keep Em Rollin'

VMVA
ez8
SGT
SGT
Posts: 175
Joined: Tue Jul 11, 2017 6:37 pm

Re: Horn in-op

Post by ez8 »

I was able to locate the wire in the steering column and test it separately, I also took NAM VET's advice and jumpered the horn to the batteries. The horn works, but the wires don't. I guess the next step is to go through and tear the steering column apart so I can run the wires through there again?
Cal_Gary
Moderator
Moderator
Posts: 4353
Joined: Mon Oct 22, 2007 5:51 am
Location: Draper, Utah

Re: Horn in-op

Post by Cal_Gary »

NO don't tear it apart! Tie a piece of floss to the top end then pull the wire out the bottom. The floss will trail behind; once you have your new wire ready to go, attach it to the tag end of the floss then pull it right back up through the steering shaft-so much easier than trying to fish it through! Also, I got a matching 12V horn from Peter DiBella Jeep parts at one of the MVPA Nationals a few years ago.
Gary
Cal_Gary
1954 M37 W/W
MVPA Correspondent #28500
G741.org Forum member since 2004
User avatar
vit16
CPL
CPL
Posts: 158
Joined: Mon Sep 28, 2020 5:22 am
Location: Argentina

Re: Horn in-op

Post by vit16 »

I wonder how it sounds!

Mine I believe is a funny "ford A" type horn heheh I believe it was installed by the previous owner and it is not original at all.
ez8
SGT
SGT
Posts: 175
Joined: Tue Jul 11, 2017 6:37 pm

Re: Horn in-op

Post by ez8 »

It sounds like any other car horn, I guess. A little deeper, maybe. It's a good sound for a horn - very authoritative. I had a Porsche 944 one time that was very fast and very noisy, but it's horn was very meek and sweet. It didn't match the car at all. :lol:
Post Reply