Jeep Wrangler Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
333 Posts
Discussion Starter #1
I mounted my air compressor inside the jeep. I op tested it and it worked fine (a few seconds). I ran a wire from the plus on the battery and another to ground. Ran the wire to behind the seats where the pump is mounted. The pump originally was a portable type I connected directly to the battery. I cut the majority of the pump's original cable and to make the connection, I spliced a quick release connector on a short piece of the same type wire I ran from the battery. I want it to be removable. I had to do this because the wire that comes from the air pump was too large to use the with the quick connect. It worked, but I had not tested it actually filling a tire. Well when that time came, the pump did not even get a single tire aired up when I saw smoke coming from the wires. It also seemed like it was not working at full capacity. It would normally air up a 35 in 3 min.

So now I am wondering if the wire I used is too small or is it because I did not solder it inside the quick release connector. It melted the wire covering on the pump side the wire going to the battery is ok. The pump is a 12 -13.5 volt 45 amp pump. Any advice on how to fix the wiring so it will not burn would be appreciated!!!

DSC_0167.JPG DSC_0169.JPG
DSC_0171.JPG DSC_0174.JPG
 

·
Registered
Joined
·
1,876 Posts
Hard to tell because of the aftermath. Could be a short caused by power and ground wires contacting one another, perhaps inside the electrical connector. Or, could be that your compressor is drawing too much current. What gauge is the wiring you used?

You should also use an inline fuse and a relay. Did you?
 

·
Registered
Joined
·
333 Posts
Discussion Starter #3
Hard to tell because of the aftermath. Could be a short caused by power and ground wires contacting one another, perhaps inside the electrical connector. Or, could be that your compressor is drawing too much current. What gauge is the wiring you used?

You should also use an inline fuse and a relay. Did you?
No inline fuse used. I assumed I did not need one since the original way to use the pump was direct battery connection. It has a reset button on the pump. I am not sure if that is fused.

Here are the two different size of wires. I am not sure what gauge. I cannot find that info stamped on the wire. Before I put in the hardwire, I connected the red connector to the battery and the switch for it was on and it started. So it is grounded by the way it is mounted.
DSCN1916.JPG
 

·
Registered
Joined
·
1,721 Posts
That wire looks way way too small to me. Plus the connector may not be making a solid connection and bottle necking the current.

If that pump is rated at 45 amps, the minimum gauge of copper wire at 76*C is 8G. That's rated for 50amps and is probably the size that is coming out of the pump. I would over size the wire and run 4 gauge wire. But I wouldn't put a connector on it like that unless you find a properly rated 45amp connector. If you run it straight from the battery it will arch like crazy when you push the connections together.

The proper and simplest way to do this would be to run 4g wire straight to the batt and put some alligator clamps on the positive and negative wires. Then when you need the pump just pop the hood and connect the clamps.

If you want it permanently inline and switchable, with either a quick connect or a rocker switch, you'll have to use a relay.

A relay runs a small current to the switch that way it doesn't arch or heat up when the switch is thrown, then it routes the full amount of juice to the accessory. This way the full load of the battery isn't being held in the switch/connection wire.
 

·
Registered
Joined
·
1,828 Posts
That wire looks way way too small to me. Plus the connector may not be making a solid connection and bottle necking the current.

If that pump is rated at 45 amps, the minimum gauge of copper wire at 76*C is 8G. That's rated for 50amps and is probably the size that is coming out of the pump. I would over size the wire and run 4 gauge wire. But I wouldn't put a connector on it like that unless you find a properly rated 45amp connector. If you run it straight from the battery it will arch like crazy when you push the connections together.

The proper and simplest way to do this would be to run 4g wire straight to the batt and put some alligator clamps on the positive and negative wires. Then when you need the pump just pop the hood and connect the clamps.

If you want it permanently inline and switchable, with either a quick connect or a rocker switch, you'll have to use a relay.

A relay runs a small current to the switch that way it doesn't arch or heat up when the switch is thrown, then it routes the full amount of juice to the accessory. This way the full load of the battery isn't being held in the switch/connection wire.
^^^^^^^^^^^This.....Just reinforcing what Bent has said, and will add
"Never go with a smaller wire gauge than what was supplied from the factory"
 

·
Registered
Joined
·
1,125 Posts
I think Bent Jeep may be correct on the wire gauge being too small.
Here is a link to a page that has a chart for how to select wire size, based on your voltage, and currant draw, and lengh of the wire. This counts the total lengh, from the battery, to the pump, and back to the battery.

DocThrock's Team Rocket F1 EVO Electrica Wiring

Keep in mind using larger wire is safer then smaller wire
 

·
Registered
Joined
·
1,721 Posts
I think Bent Jeep may be correct on the wire gauge being too small.
Here is a link to a page that has a chart for how to select wire size, based on your voltage, and currant draw, and lengh of the wire. This counts the total lengh, from the battery, to the pump, and back to the battery.

DocThrock's Team Rocket F1 EVO Electrica Wiring

Keep in mind using larger wire is safer then smaller wire
That's a nice graph.
 

·
Registered
Joined
·
117 Posts
One other thing Bent jeep didn't mention is that I would never run anything that doesn't have a fuse on it. Whether it's an air pump, a sound system amp, lights, etc. Accidents like you just experienced are going to happen; all you can do is plan for them. The fuse will drastically decrease your chances of having to replace the wiring, the component or even the entire vehicle (unchecked electrical currents can easily start fires). Just my two cents though.
 

·
Registered
Joined
·
6,202 Posts
Make sure you have a good ground. those little compressors pull a ton of amps.

I burned up an ARB harness a few weeks ago with a bad ground
 

·
Registered
Joined
·
783 Posts
Looking at the connector with the burnt wires, you can see the heat source. Where the yellowing mark is at. I'd say you had a bad connection. You need a larger connector rated over 45 Amps. And get some better wiring. You can google the wire size in Gauge and to Amps used. And if you know how to use a voltmeter, next time read the Voltage on both sides of the connector and see if there is a difference. And that's the problem you had. A real big difference. And after you run new wiring and test the pump, you should feel the wires and connector and see if they are warm or hot. YOU ARE PLAYING WITH FIRE! KINDA LIKE A TOASTER YOU MIGHT SAY. I have to ask, why would you run smaller wiring to larger wires.
 

·
Registered
Joined
·
135 Posts
The spark seem before the connector like if the wire was pinch by your seat rail or something like that. Use at least the same gauge that original and if you extend the wire, you need to upgrade the gauge following the chart. And yes, you need a fuse near your power source(battery): if your wire get cut by anything you will be safe = no jeep in fire! Are you sure for the 45amp(seem huge)? Viair 450c is rated 23amp...
 

·
Registered
Joined
·
1,721 Posts
One other thing Bent jeep didn't mention is that I would never run anything that doesn't have a fuse on it. Whether it's an air pump, a sound system amp, lights, etc. Accidents like you just experienced are going to happen; all you can do is plan for them. The fuse will drastically decrease your chances of having to replace the wiring, the component or even the entire vehicle (unchecked electrical currents can easily start fires). Just my two cents though.
Oh yeah good call. Forgot to mention that. Thx!
 

·
Registered
Joined
·
333 Posts
Discussion Starter #16
Got some larger wire (larger than original) and connectors. I also got a 30 amp inline fuse. I tested it again, but just as the pump filled the tire to capacity. About 40 psi. The fuse blew. :nonono: The pump was putting out some air this time and seemed to be back to normal speed in filling a tire.

I am now in search of a 40 amp fuse to put in. I think a 40 amp should do the trick (fill a tire without blowing the fuse) so I can do the other 3. LOL. Problem is finding that fuse here is a pain; Japan.
 

·
Registered
Joined
·
3,490 Posts
In your first post you state the pump draws 45 amps. That's why it blew the 30 amp fuse. It will blow the 40 amp one too.

Use the specifications from the pump and size everything correctly. Wire connectors, fuse and fuse holder.
 

·
Registered
Joined
·
1,828 Posts
In your first post you state the pump draws 45 amps. That's why it blew the 30 amp fuse. It will blow the 40 amp one too.

Use the specifications from the pump and size everything correctly. Wire connectors, fuse and fuse holder.
^^^^^^^^^^^^^This is correct; you must fuse to match the load!
And for 45 amps, I would be looking at a circuit breaker instead of a fuse, because the fuse will probably pop at 45.5 amps where the breaker would allow for a momentary overload.(Like starting under a load)
 

·
Registered
Joined
·
1,721 Posts
Yeah your gonna need a bigger fuse. If the pump draws a 45amp constant load, you may even need a 50amp to account for the occasional spike.
 
1 - 20 of 26 Posts
Top