Do I need a relay???

Parents got me a basic horn tech system. I’ve had Kleinn in the past, but that truck was totalled. This kit came with pretty much nothing, including no instructions. I am using a toggle switch to operate the compressor and was simply wiring one fusable link to the positive battery and through the toggle. I grounded the compressor to the chassis. I hit the switch and nothing. All of my previous horns used a relay. Is one necessary if I’m using the toggle to power the compressor?

Not sure I understand the question. Toggle vs. Relay = the same in my books; one operates via your finger, the other via an electrical current.

What kind of compressor is it? Check your switch for continuity. The way you explained the wiring it should run. Eliminate the switch to see if the compressor fires up - could be a broken compressor, faulty switch or connection.

List the parts that actually came with the kit or post a link. That way we can take a look and give you some ideas on how to wire it up.

The difference is that using a relay allows you to use a safe amount of current through the toggle switch. Most toggle switches can safely handle 10 - 20 amps (Yes, I know there are higher rated toggle switches out there) where a relay is rated 40 amps or better (up to more than 500). Most relays use ~4 amps to make them turn off/on so you would only be putting 4 amps or less through the toggle switch.

If it isn’t turning on it could be that the compressor used a current that is higher than the toggle switch rating and it destroyed the toggle.

I would NEVER run a compressor off of a toggle switch and always use a fuse close to the battery that is roughly 10% higher than the compressor maximum draw (rounded up) so if something does happen the fuse will blow and you won’t burn up your wires.

Also, make sure your wire is thick enough to handle the amp draw, many of the “premade” systems (not just horns, everything) come with wire that is barely enough to handle the load.

^ Look I totally agree with you; I wouldn’t run compressors through an SPST either but if the question is “What type of switch should I use? … a switch or a switch” the … answer would obviously be “use a switch”. The point I was trying to make is that the choice of switch type probably won’t make a diff as to why his compressor isn’t running. The topic of switch load rating is entirely separate. Use a standard automotive relay (e.g. 15A) and you’ll melt that just as quick as your toggle. As you pointed out he needs to design his whole circuit depending on the max amp rating for the compressor and not just the switch gear.

Not sure if he’s got a circuit tester or multimeter, but a simple way to troubleshoot will be to hard wire the compressor straight to the battery terminals to check that it even runs. If that works he can start to go back to diagnosing the switches.

One would hope that his kit has at least a pressure switch - so if it’s only a small unit the kit is probably designed for use as a basic circuit (i.e: Anode > Fuse > SPST toggle > Pressure sw. > Compressor > Cathode). Until we know what he’s got it’s difficult to give good advice.

If he even has an air tank… It, honestly, sounds like a kit that has an air compressor running directly to the horns… which, in my opinion, is bad to begin with…

Quite frankly, I would scrap the generic horn kit and get a shocker kit… minimum…

I agree with you that he should design the system before implementing it…

I wasn’t trying to bash you as your signature indicates you know what you are doing from the collection of various horns you have, I’m simply giving the OP a little more information that, I believe, he needs…

You are absolutely correct that he should hook it directly to the battery to see if the compressor runs without the switch, if it does, chances are it’s the switch.

Hi…i am a new user here. I think you should check your switch for continuity. The way you explained the wiring it should run. Eliminate the switch to see if the compressor fires up - could be a broken compressor, faulty switch or connection. List the parts that actually came with the kit or post a link. That way we can take a look and give you some ideas on how to wire it up.

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Hi…I would NEVER run a compressor off of a toggle switch and always use a fuse close to the battery that is roughly 10% higher than the compressor maximum draw so if something does happen the fuse will blow and you won’t burn up your wires.
Also, make sure your wire is thick enough to handle the amp draw, many of the “premade” systems come with wire that is barely enough to handle the load.

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You should always use a switch to turn the relay off and on. The relay will take the abuse of switching the high amp draw whereas a switch will fail.

-Kris

I must Emphasize, ALWAYS Use an In Line Fuse! and a Relay and Pressure switch along with your toggle switch.