Horn not working

[ghodges]

Hey everyone

I have a 98 International 3800 with the t444e.

The horn doesn't work, although the relay clicks when I engage the steering wheel switch. The horn does work when I run a jumper from the battery.

Does anyone know how the horn is wired? Is there a fuse somewhere between the relay and the horn that I should know about?

Thanks in advance - Gary

[Jolly Roger bus 223]

Sounds like it's just a fuse?
Look in your fuse panels and try to spot any that are blown?
Most likely a 10-15 amp one.
Good luck

[ghodges]

Thanks man. That was my first thought, but the horn fuse was solid.

Also, since the relay is clicking, it would seem there is power to that point.

So now I'm wondering if there might be an inline fuse somewhere or if I have a break in the wire.

[Ciscokid]

My horn is located right under the bus under driver seat. stick a volt meter on it and start tracing it backwards.

I want the train horns that flying J sells

Inside your electrical door on the side is there a wiring diagram? like this one?

[leadsled01]

What, horn doesn't work? That blows... lol couldn't resist.

[BlackJohn]

Swap the horn relay for another similar one. Or check the ground on the relay socket itself. Pushing the horn button completes the circuit to ground and that makes the horn blow if the relay is good.

Could be a broken wire running up the steering column to the horn button.

Check everything with a meter, don't be guessing.
You checked the horn already so that much works, only leaves the relay or harness.


John

[ghodges]

Yeah Cicso - My horns are located right under the radiator so tracing the wires back through the engine compartment is a bear, but that may be what I need to do.

I don't have a wiring diagram in the main compartment, but I do have the owner's manual, so I could check in there.

This might be my excuse to go ahead and get an air horn!

[ghodges]

Originally Posted by leadsled01

What, horn doesn't work? That blows... lol couldn't resist.

atleast10characters

[ghodges]

Originally Posted by BlackJohn

Swap the horn relay for another similar one. Or check the ground on the relay socket itself. Pushing the horn button completes the circuit to ground and that makes the horn blow if the relay is good.

Could be a broken wire running up the steering column to the horn button.

Check everything with a meter, don't be guessing.
You checked the horn already so that much works, only leaves the relay or harness.


John

I do have a spare relay, so I can try that. The switch does work. I'm guessing there is a problem in the harness. Joy, joy. Thanks

[TeacherJoe]

I’ll dig up this older thread...

My horn doesn’t work either. I honestly can’t say if it ever did. It’s on ‘05 Thomas FS65 with no relay. Just a fuse. With the ignition on, I read no power at the horn button wires, no power at the fuse, and no power at either connector at the the horn. There are two connectors and one horn.

Do I just need to install a new aftermarket unit?

Joe

[Walter62]

Anyone figure out the horn problem I’m having the same problem. Relay clicks when pressing horn. I found the relays down by left foot behind the plate. Swap Med out relays still same just a click no horn. Fuse good. Chase the gray wire as far as I could. Grey wire hot+ i

[Danjo]

Just use your finger

[Walter62]

I did that Danjo that’s how I know the grey wire is +. Now my Arthritis in my hands is better.

[Walter62]

Anyone ever come up with the horn not working problem? I have same exact problem relay clicks no horn jump the horn wires and horn works press the steering wheel and no horn just relay click. Also now my headlight dimmer switch stays on bright? And ideas Thank you

[magnakansas]

the wire up at the steering wheel is a grounding wire.... that way if it is broken it wont blow a fuse all the time.....

then there is a relay.


so,,,, battery hot wire goes to electromagnet coil the other side of the coil is the negative wire that goes up through the steering wheel

another battery wire goes to the horn side of the relay contacts the other side of the relay contacts goes to the horn.

press the horn button, that connects the negative side of the relay activate and that makes the coil become a magnet.

the magnet sucks the contacts closed and lets battery power flow through the relay out to the horn..
if the relay does not click test to see if horn wire is gounding and test to see if battery power is getting to relay- there should be at least one wire with power sometimes two with power..

if the relay clicks then then battery wire for the horn is not good - could be wire or fuse.. test to see if power is making it to the relay... there

or the contacts in the relay are not good -- test the relay with the horn button pushed down and see if power goes through the relay

test wire that goes to horn by connecting for a second with battery power and listen to horn..

that is a start

william call if you wanna talk diagnoses 7852077600

[Walter62]

Originally Posted by magnakansas

the wire up at the steering wheel is a grounding wire.... that way if it is broken it wont blow a fuse all the time.....

then there is a relay.


so,,,, battery hot wire goes to electromagnet coil the other side of the coil is the negative wire that goes up through the steering wheel

another battery wire goes to the horn side of the relay contacts the other side of the relay contacts goes to the horn.

press the horn button, that connects the negative side of the relay activate and that makes the coil become a magnet.

the magnet sucks the contacts closed and lets battery power flow through the relay out to the horn..
if the relay does not click test to see if horn wire is gounding and test to see if battery power is getting to relay- there should be at least one wire with power sometimes two with power..

if the relay clicks then then battery wire for the horn is not good - could be wire or fuse.. test to see if power is making it to the relay... there

or the contacts in the relay are not good -- test the relay with the horn button pushed down and see if power goes through the relay

test wire that goes to horn by connecting for a second with battery power and listen to horn..

that is a start

william call if you wanna talk diagnoses 7852077600

Thank you for your explanation MagnaK