Air Horn install on 1990 International 4900

[PeterG]

Need help with installing a Fulton Air horn on my International 4900 truck with air brakes. The question is, can I run the air line down to the air seat area, and tie into that air line, or do I need to go all the way back to the air tank? Anyone have any images of how they ran the pull cord set up in their International 4700-4900 truck, or where the horn is mounted on the roof upper left side? Any tips would be much appreciated. Thanks.

 

[redneckracin]

Following, I have the pull cord and supply line in the roof of the truck, but i need to mount the horns!

 

[funwithfuel]

Your seat should be fed by your "wet tank" if memory serves. So you should "Tee" in to that as a supply. That way your brakes pri and sec tanks are protected from air loss.
BTW I have seen very clean installs using a relay and air solenoid. Just use your existing horn circuit to activate. Alleviates the problem of cutting up your headliner, running air up and back etc. Just a lil sumthin to think about.

 

[RZucker]

Your seat should be fed by your "wet tank" if memory serves. So you should "Tee" in to that as a supply. That way your brakes pri and sec tanks are protected from air loss.
BTW I have seen very clean installs using a relay and air solenoid. Just use your existing horn circuit to activate. Alleviates the problem of cutting up your headliner, running air up and back etc. Just a lil sumthin to think about.

Saw a Volvo awhile back with a pull cord overhead... The horn was back under the sleeper... WTH?

 

[kshansen]

Your seat should be fed by your "wet tank" if memory serves. So you should "Tee" in to that as a supply. That way your brakes pri and sec tanks are protected from air loss.
BTW I have seen very clean installs using a relay and air solenoid. Just use your existing horn circuit to activate. Alleviates the problem of cutting up your headliner, running air up and back etc. Just a lil sumthin to think about.

On the idea of using the electric horn button to control a solenoid valve to work an air horn. I would check with DOT on deactivating an electric horn. Not sure if there is some regulation that may be involved. Many years back I recall one of our drivers getting into a problem with DOT about the fact that the electric horn did not work on a Mack tractor.

 

[Birken Vogt]

On the KWs I used to drive there was a switch on the dash that made the air horn blow when it was on and only the city horn blew when it was off. But it did not disconnect the city horn, they just both blew at the same time but nobody could hear the city horn over the racket.

 

[PeterG]

Thanks for your replies. The truck has a very weak electric horn, with a horn button installed on the dash by someone. It does pass DOT. I suppose I could just get a better electric horn, but I always wanted a real air horn with a pull cord. Today I will install the air horn. I picked up a DOT Parker Prestomatic Union T and Parker Tube Cutter and plan to tie into the air line going to the drivers air seat inside the cab just where it comes into the truck cab. There is a panel access opening above the drivers door, so i will try and run the air line inside the panel to behind the seat. The only real scary part is drilling two holes in the roof!

 

[funwithfuel]

So that looks like an S series Cab O there should be a small two screw cover just above the left side door panel And the header you should be able to remove that And mount your valve there. That would make for a factory installation after the fact

 

[funwithfuel]

And that is exactly what I was thinking about however I neglected to mention leaving the electric horn in place

On the KWs I used to drive there was a switch on the dash that made the air horn blow when it was on and only the city horn blew when it was off. But it did not disconnect the city horn, they just both blew at the same time but nobody could hear the city horn over the racket.

 

[PeterG]

I did open the two screw hole cover, and cleaned out a mouse nest. There was a hole in the roof when I got the truck. Looks Like I will need to drill a 1/4" hole near the cover, then pass the air line up or down. So what is the best way to do that? The plastic is stiff, so I suppose the best way is to drop a fish tape down to the bottom, and then pull the air line up?

 

[funwithfuel]

Its been forever, i believe the line ran up the "B" pillar left side. Its a long way to go, that's for sure. And yes, fish tape is the only way to go.

 

[PeterG]

Ok, so start with the fish tape in the bottom hole and try and get it to come out the top by the two screw panel opening? Then pull the fish tape out with a string line attached. Then drop the fish tape back down from the top pulling it out the bottom hole with the string, then pull the air line up. Otherwise I think it may be super hard to see and find the fish tape on the bottom less I make a giant hole if I just started with the fish tape from the top. Ideas?

 

[funwithfuel]

No, too complicated. Fish back and down along roof sill to b pillar. The natural curve in the back corner should help guide it. You could also remove the csrdboard headliner. I think theres 4-5 screws across the back. Good luck

 

[Birken Vogt]

About 15 years ago I installed some wires to the headliner on a similar truck. It was such a miserable experience I decided I would never do that again. Something about 2 layers of steel in the cab and things just were not working out. Maybe I chose the hard way but it was real bad. If you had that truck over to me I would try to talk you into installing the horn in the bumper or something.

 

[kshansen]

If I was to make a wise a$$ remark I would say something about finding the mouse that built the nest and tie a string to his tail then hold a piece of cheese down at the bottom of the cab. But being a nice guy I will refrain from making those kid of remarks!