Originally Posted by axplayer
I have an ARB compressor I'm installing under the hood of a 2013 JKU. I'm running the air fitting and a switch somewhere in the vicinity of the front bumper so I can fill toys, tires, etc., without having to open the hood, get inside, etc. If I run + and - right to battery with the 40A fuse it came with (and a switch, of course), do I need a relay? Thanks.
I found your post searching for onboard air.
Keep in mind that if you do this that your switch has to be rated for whatever the amp load will be. So if compressor is a 40a compressor, get a switch that is rated 40a or higher.
I'm just starting my search, but I would think compressor should have an ignition wire or a trigger wire so it only runs when the wire receives a 12v power (or in some cases ground) input signal. If its only two wires then your options are as follows:
1- As you stated above, inline switch rated for amp load.
2- relay that supports the amp load (i.e. 40a). Relays basically have a high power side and low power side. Benefit of a relay is you can use a very low input signal to "connect" the high power contacts together and turn compressor on.