Seneca -air horns

MD3 · 10-05-2017, 06:33 PM

Looking at adding a set of air horns on my Seneca.
Any ideas where I should pull the air from ?
The air horns require a 1/4" air line and I see a couple 1/4" air lines that would be easy to T off of but not sure which would be the best one.

-

RyRoRyan · 10-05-2017, 08:37 PM

SORRY FOR THE CAPS RIGHT OFF THE BAT, BUT DONT TOUCH THOSE AIR LINES!!!!

Those lines are for your air brakes. I have done this mod as well as many others on this forum. The BEST way to do this is to do it through a pressure protection valve directly connected to the air tank. The pressure protection valve will allow the internal system to still have pressure in case your air horn hose fails in any case. I can explain how to do it, but I think Robby's mod post pretty much says it all...

https://www.jaycoowners.com/forums/f...ill-35437.html

MD3 · 10-05-2017, 09:31 PM

Thank you for the link !
Two airlines run into the cab and do not run through the brake valve but not sure if those are associated with the brakes somehow also....
I'm going to have to rethink my entire install after reading the link.

-

MD3 · 10-06-2017, 12:40 AM

After reading the link I'm thinking about running a pressure protection valve off an exsisting air tank. Then run the air line to a splitter/T and then to a quick connect coupler and to the air horns.
This will protect the air system in case I get a leak at my quick connect air fitting or my air horns.

Next question (not answered in the link above) : which air tank do I run off of ??
I have two tanks but not sure how to tell what air tank is primary or secondary and which is best to run these accessories off of.

-

Robbbyr · 10-06-2017, 07:03 AM

I can't help with a definitive answer on the air tank to use since my Seneca is a 2014 with 4-wheel hydraulic disc brakes. Jayco switched to air brakes in 2016. I tapped into the so-called "wet" tank, which is the first tank the engine air compressor dumps into.

I can say some of the fire trucks I drove also took the air horn supply off of the wet tank, and they obviously had air brakes. My mechanics that serviced our fire trucks are the ones who strongly recommended the installation of the PPV to protect the air system since, while I don't have air brakes, I do have an air parking brake that (like yours) will come on if there is a loss of air. Very bad if traveling down the road!

I thought another newer Seneca owner did post pictures of where he tapped in, the tank had several unused (plugged) ports that he was able to use to plumb in his PPV and then go from there. I also have a regulated fill station tee'd into my system, has proven very useful. I would suggest that, from whatever tank you source the air, you come off with a nipple right into the PPV rather plastic brake tubing to a remote-mounted PPV. Less chance of leak issues later.

I also added another storage reservoir after my PPV and my horn/fill station line comes off that. Possibly overkill, but that is the way I think! I also did a dash switch allowing me to select either air or electric horn. But I can say 99% of the time it is on air!

Robbbyr · 10-06-2017, 07:09 AM

I forgot to mention my Seneca also has those (other) air lines, not attached to your foot brake (treadle) valve. They go inside to my dash-mounted parking brake valve, and likely do the same in a newer air brake-equipped unit. So don't mess with those either!

RyRoRyan · 10-06-2017, 07:23 AM

I put mine on the tank on the drivers side closer to the front of the vehicle. Since we dont have a wet tank dry tank setup and since the front and rear brakes run off different tanks, I didnt think it would really matter which tank I used. The PPV I used will keep 80 PSI in the tank if a failure did happen which is more than needed to keep the park brake open so I know I wont have a rear tire lockup. In any case, here is a picture of my tank and my finger is over the hole I used to mount my PPV. I ran a hose directly from there to the front passenger side and then mounted a pressure regulator then a tee which goes to the horns and an air chuck. I didnt go as high tech as Robby did, I just wired my air horn directly to the electric horn wires. Yes I know I cant turn the air horns off, but in all reality, if I actually need to use the horn it better be noticeable. Its not like these are delivery route trucks which can regularly use elec only horn to give indications of backing up, and be a more polite way of letting a dock employee that you have arrived. Air horns in those circumstances are a little over kill.

Edit...not sure why the forums do this, but my uploaded images get turned 90 degrees. Turn your head to the left 90 to view this up and down. The plug my finger is on is the one that is closest to the outside of the vehicle.

MD3 · 10-06-2017, 08:28 AM

Thank you for all the info !!

I need to find out the max pressure for my air horns to see if I need the pressure regulator or not.

I'm going to order the ppv valve linked from Amazon but the description is lacking a lot of info. Hopefully it will work as described.
https://www.amazon.com/gp/product/B0...ZLMPRJFH&psc=1

I'm also going to run this switch. I will have both horns working when the air horn is selected but when I want to have a little beep horn at my neighbors I can kill the air horn.
https://firelineequipment.com/produc...itch-air-horn/

Great info, great write ups !!
I'm glad I asked before just trying to plug these horns in.

-

ed4ster · 10-06-2017, 04:33 PM

MD3 when I performed the air horn mod I tapped into the air line under the passenger seat. This would save you having to purchase the related hardware when running a direct line from one of your air tanks. Attached is a Freightliner dwg. that shows that you can tap into either air line for the air seats if equipped.

Robbbyr · 10-06-2017, 04:41 PM

I believe he has a 2018 (pre-S2RV) and I also believe Jayco discontinued the air seats by then.

So underneath he goes!

MD3 · 10-06-2017, 04:44 PM

Yes, no air seats. I'm going to have to route it from the tank.
Thank you for the idea though.

-

javamon · 01-14-2024, 02:48 PM

Quote:

Originally Posted by RyRoRyan

I put mine on the tank on the drivers side closer to the front of the vehicle. Since we dont have a wet tank dry tank setup and since the front and rear brakes run off different tanks, I didnt think it would really matter which tank I used. The PPV I used will keep 80 PSI in the tank if a failure did happen which is more than needed to keep the park brake open so I know I wont have a rear tire lockup. In any case, here is a picture of my tank and my finger is over the hole I used to mount my PPV. I ran a hose directly from there to the front passenger side and then mounted a pressure regulator then a tee which goes to the horns and an air chuck. I didnt go as high tech as Robby did, I just wired my air horn directly to the electric horn wires. Yes I know I cant turn the air horns off, but in all reality, if I actually need to use the horn it better be noticeable. Its not like these are delivery route trucks which can regularly use elec only horn to give indications of backing up, and be a more polite way of letting a dock employee that you have arrived. Air horns in those circumstances are a little over kill.

Edit...not sure why the forums do this, but my uploaded images get turned 90 degrees. Turn your head to the left 90 to view this up and down. The plug my finger is on is the one that is closest to the outside of the vehicle.

In the process of ordering air tank fittings to install my MPC air horn. Does anyone recall the thread size of the air tank ports. I'm thinking 1/2" but not sure. Thanks!

Jeepin Jason · 01-14-2024, 02:55 PM

For the newer Seneca's that come with the air horn, can you just tee off that line and add an additional horn set? This way it would work with the OEM pull in the cab.

javamon · 01-14-2024, 02:57 PM

Quote:

Originally Posted by Jeepin Jason

For the newer Seneca's that come with the air horn, can you just tee off that line and add an additional horn set? This way it would work with the OEM pull in the cab.

I'm in a 2017, no existing air horn and no air seats. Have to come off secondary air tank.

Jeepin Jason · 01-14-2024, 03:41 PM

Quote:

Originally Posted by javamon

I'm in a 2017, no existing air horn and no air seats. Have to come off secondary air tank.

Thanks, I understand that, was asking the question in hopes someone with a newer model could shed some light to the installation requirements.

Rustynuts · 01-14-2024, 04:17 PM

Quote:

Originally Posted by Jeepin Jason

For the newer Seneca's that come with the air horn, can you just tee off that line and add an additional horn set? This way it would work with the OEM pull in the cab.

On the S2 chassis it’s as easy as swapping out a factory coupler for a tee. On the drivers side firewall, but the steering column, you should see a yellow air supply line that runs up to the air horn lanyard valve, and then a black line which runs from the valve to the factory air horn. You can simply put a tee in the yellow line where the factory coupler is. I replaced my factory air horn with a set of train horns and with the tee’d off line I have an electric solenoid wired to the steering wheel button and this controls a Cunningham 1A air whistle.

You may also like: