Loud noise!

[ROARKY]

So I drained my air tanks free running my 1970 m35a2. After draining the tanks, I also replaced the light switch and discovered that the wires were broke right before the flasher Relay. After putting it back together, I started up the truck and after 20 seconds or so, it started howling super loud! I could only get it to stop by turning the truck off and bleeding the air tanks. I have never heard the horn on this truck but I was wondering if it may be it? Any suggestions?

 

[WILDBOY6X6]

Hummm that might be it, try unplugging the wire on the horn and see if the noise stops, it might also be coming from the compressor although I dought it.

 

[davidb56]

are you sure your not hearing the low air pressure alarm?

 

[WILDBOY6X6]

That would happen till the air builds up all the way yup, but how many still work LoL

 

[montaillou]

I have never heard the horn on this truck...

I couldn't drive w/o the horn and of course, my middle finger.

 

[rustystud]

I couldn't drive w/o the horn and of course, my middle finger.

That got me laughing ! Thanks Montaillou !

 

[gimpyrobb]

Yes, sometimes the solenoid sticks open.

 

[ROARKY]

No it’s definitely not the low pressure alarm, it was working as well. This sounded like it was coming from near the center front of the cab. It was so loud that I could not pin point the location. I am going to look at it again this morning.

 

[Barrman]

The air regulator is on the engine side of the firewall pretty much in the middle. But they click and thunk. Not howl.

Look under the radiator at the frame rail on the drivers side. That is where the horn wire comes out of the steering column shaft. That wire is hot at all times so put on rubber gloves or use insulated tools. Look at the wire coming out and see if it has rubbed enough to ground through all the goo, muck and grease down there. Again, be careful. 24 volts hurts when it bites.

 

[TehTDK]

I thought the horns on the deuce was air operated.

 

[ROARKY]

So I figured out what the culprit was. As some of you suggested, the wire to the horn had actually broken. It appears that in my messing around I managed to get it to short. I unhooked both wires and that solved the issue.

 

[Nomad1]

the horn it self but not the button

I thought the horns on the deuce was air operated.

 

[TehTDK]

Ah gotcha. So the button actuates a butterfly valve or solenoid that lets the air flow into the horn?

 

[glcaines]

Ah gotcha. So the button actuates a butterfly valve or solenoid that lets the air flow into the horn?

Yes