On Board Compressor

I have finally selected and installed an on-board compressor. I selected a Mean Green 2Air from Opposite Lock (they were on special). It pumps my tyres from 24psi to 30psi in 25 seconds.

I have attached some images to show how I have installed it. I have used 6mm tubing to go to the pressure switch because the compressor is on the opposite side to the battery and it meant less wire. I ran the wire for compressor through 10mm loom tube with the 6mm tubing to make for a very neat finish. Power is connected to battery via 50A fuse and 40A relay. I have attached a circuit if anyone is interested.

I also have an air point at the front on the bullbar (using 8mm tubing through grill). To prevent any dirt or muck getting into connector, I use 25mm chair leg rubbers from bunnings and a bit of foam hose.

I no longer need to pop the bonnet to pump my tires up now.

I hope this can be of some help to others.

Just a note, connect the negative of the compressor straight to battery and not through chassis. The compressor draws more than 30A (I know because it blew 30A fuse - also, compressor specs say it draws 32.6A), and you don't want that much current going through your chassis for any period of time.

You can use rubber door stops to cover the outlet from getting full of shite

I've got a pump that looks exactly like that on here in UK land ;) On mine the switch is on the pump. So if I can find a pressure switch I could do as you have , cool. Now where can I get a pressure switch ? Does it sense some tyre pressure to fire it up ? If so how does it work if the tyre is flat ?
Electrickery is not my strong point ? lol

The pressure switch is situated in the output side of the compressor and is pre-set so it will cut the compressor out when that pressure is reached. Angelo, where is the air filter for the inlet. I was going to run a hose and fit the filter inside the cab on the passenger side fire wall, but I mounted the compressor under a rear passenger seat.

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Originally Posted by angelo_f

Just a note, connect the negative of the compressor straight to battery and not through chassis. The compressor draws more than 30A (I know because it blew 30A fuse - also, compressor specs say it draws 32.6A), and you don't want that much current going through your chassis for any period of time.

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Why is this?

i only ask as i run a twin arb compressor with the neg through the chassis and have had no problems, about 60A too.
But do not want one either.

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Originally Posted by makeitfit

I've got a pump that looks exactly like that on here in UK land ;) On mine the switch is on the pump. So if I can find a pressure switch I could do as you have , cool. Now where can I get a pressure switch ? Does it sense some tyre pressure to fire it up ? If so how does it work if the tyre is flat ?
Electrickery is not my strong point ? lol

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I got the pressure switch off ebay
http://www.ebay.com.au/itm/VIAIR-90-...item337cfa474a

The way it works is like this (Keep the switch on the actual pump on)
Initial condition -there is zero air pressure and rocker switch is off

1 - Turn the rocker switch on and your motor (or accessories) on. Power runs from accessories through the rocker switch, through the pressure switch contacts, through the relay and energises the relay, thus closing relay contacts and allowing power through compressor.
2- When the pressure in the system reaches the 'off' pressure on the pressure switch (int the case of the one I have shown in link - 120psi), the contact on pressure switch opens, causing the relay to de-energise, opening the relay contact and stopping power to the compressor.
3- As you use the air, the pressure drops to below the 'on' setting (in the case of the one I have shown in link - 90psi), the contact on presure switch closes again and the relay is energised again turning compressor back on.

Use an inflator with a gauge like this one to pump the tyres up.
http://www.supercheapauto.com.au/onl...d=293784#Cross

Also, make sure you use a relay and don't just use the pressure switch to supply the power. Those pressure switches are only rated at 20A

Are you running a tank??

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Originally Posted by Shaun 4x4

Why is this?

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Here is a good answer
http://www.city-data.com/forum/autom...d-problem.html

Basically, with that much current, you want as few points of contact as possible. If you connected through chassis, how much paint do you have there. You really should rub back to bare metal or you will get a voltage drop. When it gets wet, you will start getting electrolysis at those currents which could corrode in time.
Better to just connect to battery

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Originally Posted by threedogs

Are you running a tank??

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No need to. Also, makes it simpler and uses less space.

I see now you have closed off the system , so it holds pressure in the lines.
I would be fitting a small tank underneath, to run locker if needed, air horns ,etc
But your system will work now you only need 2mtrs of hose to reach all 4 wheels.

Also some compressors wont work when needed because of high under bonnet temps

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Originally Posted by mudnut

Angelo, where is the air filter for the inlet. I was going to run a hose and fit the filter inside the cab on the passenger side fire wall, but I mounted the compressor under a rear passenger seat.

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Mine has the filter screwed onto the side. The compressor is quite high so it won't get much rubbish in it. But it is a good thing to consider - I should see about how to make it easier to check and clean

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Originally Posted by threedogs

I see now you have closed off the system , so it holds pressure in the lines.
I would be fitting a small tank underneath, to run locker if needed, air horns ,etc
But your system will work now you only need 2mtrs of hose to reach all 4 wheels

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This is the best part - the compressor came with good quality hose (That is the green hose you can see) so I cut it and used that as my hose.

KIS is always good well done

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Originally Posted by angelo_f

I got the pressure switch off ebay
http://www.ebay.com.au/itm/VIAIR-90-...item337cfa474a

The way it works is like this (Keep the switch on the actual pump on)
Initial condition -there is zero air pressure and rocker switch is off

1 - Turn the rocker switch on and your motor (or accessories) on. Power runs from accessories through the rocker switch, through the pressure switch contacts, through the relay and energises the relay, thus closing relay contacts and allowing power through compressor.
2- When the pressure in the system reaches the 'off' pressure on the pressure switch (int the case of the one I have shown in link - 120psi), the contact on pressure switch opens, causing the relay to de-energise, opening the relay contact and stopping power to the compressor.
3- As you use the air, the pressure drops to below the 'on' setting (in the case of the one I have shown in link - 90psi), the contact on presure switch closes again and the relay is energised again turning compressor back on.

Use an inflator with a gauge like this one to pump the tyres up.
http://www.supercheapauto.com.au/onl...d=293784#Cross

Also, make sure you use a relay and don't just use the pressure switch to supply the power. Those pressure switches are only rated at 20A

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Brilliant explanation thanks a lot :) I'm all enthused now and will fit mine this weekend . KIS indeed cheers ;)

Do these have a temp cut off?? Or are they made for under the bonnet??
I bought one similar, a portable though. And mounted it under the bonnet.. It never worked due to the temp cut off.
Was lucky enough to get a replacement, but only coz I knew the sales bloke..

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Originally Posted by angelo_f

Mine has the filter screwed onto the side. The compressor is quite high so it won't get much rubbish in it. But it is a good thing to consider - I should see about how to make it easier to check and clean

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I asked because dust will quickly clog the filter, and also heard of the compressors working parts failing because of dust acting as an abrasive on them.

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Originally Posted by Westy's Accessories

Do these have a temp cut off?? Or are they made for under the bonnet??
I bought one similar, a portable though. And mounted it under the bonnet.. It never worked due to the temp cut off.
Was lucky enough to get a replacement, but only coz I knew the sales bloke..

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It was not designed for under bonnet. However, if you are worried about temperature, just pop the bonnet.

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Originally Posted by mudnut

I asked because dust will quickly clog the filter, and also heard of the compressors working parts failing because of dust acting as an abrasive on them.

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It has a filter that can be cleaned and replaced. Remember, however, that you are not running the compressor while you are driving, but when you are stopped (as opposed to your engine air filter). But it is still a good point

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Originally Posted by angelo_f

It was not designed for under bonnet. However, if you are worried about temperature, just pop the bonnet.

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No mine broke the temp cut off device. Even once cooled to ambient temp it was still dead lol.

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Originally Posted by makeitfit

Brilliant explanation thanks a lot :) I'm all enthused now and will fit mine this weekend . KIS indeed cheers ;)

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If you like that explanation, I have a circuit and explanation to give a warning if you left your lights on

http://www.nissanpatrol.com.au/forum...Lights-Warning

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Originally Posted by threedogs

Are you running a tank??

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I am not convinced a tank would be worth the effort. The tank behaves like the cistern in the toilet. In the toilet, a low flow rate of water goes into the cistern and when you press the button, you get a big flow rate for a short period of time. This works great when you only need a small total volume of water. In the case of the tyres, this would be likened to using a cistern interface when filling a swimming pool. For the short duration that it supplies water, it is really negligible.

In the same way with the tank, if you need a short duration of a high flow rate, a tank is definitely beneficial. However, with the tyres, you have to consider the maximum pressure you are really going to get will be the maximum of what the pressure switch is - in this case, 120psi. My compressor says in specs that it has > 200psi and a flow rate of 71 l/min. There may be a slight improvement in filling all the tyres in that the compressor is still working while moving between tyres, but I don't think it would be much. It may be worth while doing an experiment to see by putting a tank in line and comparing results in filling all four tyres

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Originally Posted by angelo_f

I am not convinced a tank would be worth the effort. The tank behaves like the cistern in the toilet. In the toilet, a low flow rate of water goes into the cistern and when you press the button, you get a big flow rate for a short period of time. This works great when you only need a small total volume of water. In the case of the tyres, this would be likened to using a cistern interface when filling a swimming pool. For the short duration that it supplies water, it is really negligible.

In the same way with the tank, if you need a short duration of a high flow rate, a tank is definitely beneficial. However, with the tyres, you have to consider the maximum pressure you are really going to get will be the maximum of what the pressure switch is - in this case, 120psi. My compressor says in specs that it has > 200psi and a flow rate of 71 l/min. There may be a slight improvement in filling all the tyres in that the compressor is still working while moving between tyres, but I don't think it would be much. It may be worth while doing an experiment to see by putting a tank in line and comparing results in filling all four tyres

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If all you are doing with the compressor is airing up then there is no need for a tank. If you want to fit air lockers down the track though the tank will be a winner for that. A Tank will also provide you a small burst of air in the event you are trying to reseat a tyre that you have stripped off in a rut (common) or want to run a rattle gun or other air tool or air gun.

In relation to the "claimed" output of the compressor and the airup time you quote, have you put a stop watch on that? What size tyres?

I have a pair of tanks under my rear seat that I have on an isolation gate valve and if needed can use for seating a bead. When airing up all I'd does is add volume to the airup and therefore time to pump.

Yes - You have a good point about reseating a tyre. All I am doing is pumping tyre.

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Originally Posted by angelo_f

Yes - You have a good point about reseating a tyre. All I am doing is pumping tyre.

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A quick squirt of WD40 or Easy Start, followed by a flame = a very quick andsimple tyre pop back on the rim ;)

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Originally Posted by makeitfit

A quick squirt of WD40 or Easy Start, followed by a flame = a very quick andsimple tyre pop back on the rim ;)

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Not 'dissing you', mate, but doing that on a fire ban day, could land us a huge fine in this fine country, or worse, start a fire. Would be okay any other time though.