So, 2018 ram 2500, 3 chime outlaw type horn, 2 gal compressor (127h) 1/2" 12v n.c. solinoid valve and line . Solinoid valve is hard piped to tank, then 1/2" line to the horn. When i press my horn button, the horns almost wheeze, have to depress the button 2-3 times to get them to honk properly.
My question is
A: does distance of valve from horn matter? ( currently they are about 4 feet apart)
B: could the valve not be opening properly?
C: could it be overpressurizing the diaphragms in the horn?
Any help would be greatly appreciated
Edit, its the MC2H compressor. Valve opens fine, but dumps pressure so fast through the 1/2" line that it starts running immediately. Side note, the “60 second recovery time” is nonsense.
Thanks for all the details — that really helps paint the picture. Sounds like you’ve put together a solid system, but there are a few things going on that could definitely explain the performance issues with your Outlaw horns.
Let me break it down based on your questions:
A: Does the distance of the valve from the horn matter?
Yes, absolutely. The further the valve is from the horn, the more lag and pressure drop you can experience, especially during that initial blast when air is moving rapidly. Four feet of 1/2" line can allow a brief pressure dip before the horns get the full hit, which could cause the “wheezing” sound you mentioned. Ideally, you want the solenoid valve as close to the horn as possible for best performance.
B: Could the valve not be opening properly?
If the valve opens at all, it’s probably functioning — but if the internals aren’t flowing freely (e.g., partial blockage or restriction), you could still see performance issues. That said, from your edit, it sounds like it is opening, just dumping air so fast that the compressor kicks on instantly — more on that below.
C: Could it be overpressurizing the diaphragms?
It’s unlikely unless you’re running over 150 PSI. Most horns like the Outlaw can handle up to 150 PSI without issue, and too much pressure typically leads to a higher-pitched, shrill tone — not a wheeze. If anything, low pressure or inconsistent flow causes the wheezy sound you’re describing.
Additional Notes Based on Your Edit:
The MC-2H kit with a 2-gallon tank and a 127H compressor isn’t a bad starter setup
Here’s what I’d recommend:
- Try relocating the valve closer to the horn (as short a run as possible).
- Make sure all fittings are leak-free and your tank is hitting full pressure before testing.
- If the tank is draining in one blast, you might want to upgrade to a larger tank (3–5 gallons) or run a dual compressor setup for quicker recovery.
- Lastly, if you’re using the stock horn button, ensure it’s not causing inconsistent actuation. Sometimes it’s better to run a dedicated momentary switch for full control.
Important tip:
Make sure you’re regularly draining your air tank — especially in humid environments. Moisture buildup inside the tank can not only shorten the life of your components, but it can also lead to that “wheezing” or muffled sound as water restricts airflow through the solenoid or even the horns themselves. A quick tank purge every few days or after heavy use can make a big difference in performance.
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Switched to 3/8" line and its working again. I do need to add a pressure gauge so im sure of working pressure. May need to replace the diaphragms. But the horn itself was free so i cant complain i suppose.
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