Portable Air Compressor Hardwired??
03-07-2010, 06:37 PM
#1
JK Super Freak
Thread Starter
Portable Air Compressor Hardwired??
So I have a 12v-150psi, 30amp, portable air compressor from Harbor Freight w/the 30’ hose. Was wondering if anyone had or has one hardwired (any portable compressor)? All you electricians out there help me out some. Since the compressor runs by connecting the clip to the positive terminal and the other to a neutral ground and flipping the switch on. Can I hardwire the lines to the positive lead and a ground, run the wires through the firewall and mount my compressor in the rear compartment. Then splice the factory compressor switch and run it back up to one of my daystar switches on the panel? Is that it or is it more complicated than that? Relay needed or not? Thanks in advance.
03-07-2010, 06:58 PM
#2
JK Freak
I'm no electrician, but I have learned the valuable lesson of using a relay for heavy loads. Also heavy gauge wires to avoid heat and voltage drops.
I'm guessing you want to control from the cab so you can get it juiced up before you need it?
I'm guessing you want to control from the cab so you can get it juiced up before you need it?
03-07-2010, 07:05 PM
#3
JK Super Freak
You can hardwire the compressor. The one thing you did not mention is a fuse as close to the battery as possible.
Relay is needed. When you tear in to the compressor to parallel the switch, see if there is already a relay there. If there is, just add a switch in parallel. If there is not a relay add one to the motor hot lead and use your own switch from the cab.
Relay is needed. When you tear in to the compressor to parallel the switch, see if there is already a relay there. If there is, just add a switch in parallel. If there is not a relay add one to the motor hot lead and use your own switch from the cab.
Last edited by Vernnz; 03-07-2010 at 07:10 PM.
03-07-2010, 08:08 PM
#4
JK Super Freak
Thread Starter
Thanks for the advice fellas, yeah I forgot to mention the compressor does have a 30amp fuse. Also I do want to control it with a switch in the cab.
03-08-2010, 04:37 AM
#5
JK Enthusiast
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You can, but it is highly undesirable.
Where is the compressor going to be? The closer it is to the power source, the better.
You need to run a power wire to the compressor, through a simple $4 relay. Think of it as a remote switch. Your wire to the compressor must be of a size to support the 30 amp fuse properly, about 10 gauge, so it won't get so hot as to blow the fuse, melt the insulation, and ground out causing all sorts of other issues. The further it is away from the battery, the more heat it will create, and larger gauge wire required.
From the relay, run your small, low voltage wires to your switch.
This method is a much safer, easier, and actually cheaper than running the large gauge wires all the way to a 30 amp rated switch on the dash.
Where is the compressor going to be? The closer it is to the power source, the better.
You need to run a power wire to the compressor, through a simple $4 relay. Think of it as a remote switch. Your wire to the compressor must be of a size to support the 30 amp fuse properly, about 10 gauge, so it won't get so hot as to blow the fuse, melt the insulation, and ground out causing all sorts of other issues. The further it is away from the battery, the more heat it will create, and larger gauge wire required.
From the relay, run your small, low voltage wires to your switch.
This method is a much safer, easier, and actually cheaper than running the large gauge wires all the way to a 30 amp rated switch on the dash.
Last edited by Slippery; 03-08-2010 at 04:43 AM.
03-08-2010, 05:32 AM
#6
JK Super Freak
Just so I'm clear here...You need another fuse as soon as the wire comes off of the battery. The fuse in the compressor will protect the compressor. If the supply line (you are going to add from the battery) shorts out and there is no fuse at the battery it will heat up and catch something on fire.
03-08-2010, 05:54 AM
#7
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I have the same compressor - I think I paid $59? Sweet deal. I've been thinking about what exactly I want to do with mine.
One thing to keep in mind is that the compressor has no pressure switch. You can't even put an air chuck on it because you can't cut off air flow without smoking the pump. This sort of limits it's usefulness as a permanently installed compressor.
I plan to get a engine compartment mount and attach the compressor there with easily removed wingnuts. I'm going to keep the batttery cable clamps, and just hook it up to the battery when needed. That way, I still pass it off as a portable if someone else wants / wants to use it.
One thing to keep in mind is that the compressor has no pressure switch. You can't even put an air chuck on it because you can't cut off air flow without smoking the pump. This sort of limits it's usefulness as a permanently installed compressor.
I plan to get a engine compartment mount and attach the compressor there with easily removed wingnuts. I'm going to keep the batttery cable clamps, and just hook it up to the battery when needed. That way, I still pass it off as a portable if someone else wants / wants to use it.