Poor man's OBA

Aight

Aight, thank you man!

 

Also, would I need a relay?

 

A fuse or breaker at least on the B+ terminal. Use a relay if you want it switched. Since my set up includes a tank I have a pressure switch and rocker switch in the switch circuit that controls a relay fed from a fuse.

 

Love it man!

I've been thinking about manufacturing a mount to hold two of these little guys. In the case i did this, would your manifold still work, except where the NPT plug is, id just add an additional NPT fitting to connect the second compressor to?

 

Yea man that’ll work, just need both compressors going to the manifold.

 

Thanks for great article, I am currently in process of building almost exact setup.

However prices have changed and if I didn't have the 88p compressor already I would have to think twice about spending my time on procuring every component or just buying

$318 ARB CKMA12 On-Board Air Compressor High Performance 12 Volt for Air Locker Differentials and Tire Inflation

ARB CKMA12 compressor.

Here is how it looks for me (all prices in Canadian dollars, tax included):
$165 for all components
$97 for compressor (current compressor price is $157)
Total: $260 (with current compressor price that would be ~$320)

ARB CKMA12 retails ~$480 (tax in, no discounts). In US it retails for ~$290 USD + tax. Which would mean that I can get one for ~ 420 CAD.

At the end of the day price difference is only $100 and correct me if I am wrong, but ARB comes with wiring and switch for cabin + seems to be a better quality product. (Yes, you will need adapter + plug + hose can be bought from ARB too or just somebody from Amazon, probably looking at additional $20-30 for no name and ~$40 for ARB).

Yes, there are probably ways to "save" on prices, by spending my time ($) on searching for cheapest place to buy components from. But at the end of the day it seems that it makes more sense to go with ARB (or maybe there is similar cheaper option) that is sold as package at this point with prices as they are. If only you like DIY projects and then that's a different discussion as saving seem to be very minimal.

 

$100 is ~30% which isn’t trivial either in relative or absolute terms.

 

True. However it depends how much you value your time and where you put your $/h rate too.

Trying to find and order all parts separately takes time + assembly can be challenging (if something doesn't want to work with something...) vs getting all in one package.

Also it appears that for extra $100 you are getting better product (I have ARB pump in my van and can't complain about build quality) + wiring/switch + a product that will be able to handle (is built for) air lockers if you ever go that way.

 

Is this what you mean per your description?? Thanks

 

Yes! That's exactly it!

 

so awesome just found this and now have a winter project. thank you

 

Awesome info, and very easy project. Just completed this about an hour ago . Question, how would I go about adding a tank? Would I have to run the supply from compressor to tank, then tank to manifold? Thanks!

 

Typically the compressor feeds directly to the tank starting with at least 18” of SS braided sleeve hose to prevent that section from failure due to heat. Air goes into the tank through a one way valve (back flow preventer) since many compressors can leak pressure through the intake/exhaust ports when not running. From the tank you have a drain cock at the lowest point for condensation and any other ports needed or just one to a manifold. If clean, dry air is needed it’s necessary to install a water/oil separator/filter between the tank and the manifold and someplace you can service it(drain & clean the filter). There are other ways you can do it such as putting a two way valve after the SS hose so that you can avoid filling the tank when you’re airing up tires.

 

sub

 

If you were to want to hook up a tank how would that differ plumbing wise?

 

There’s more than one way to do it but the simplest is to run the output of your compressor through a moisture filter and check valve to the tank and from the tank supply your needs. The downside to this is while the tank is full or nearly so it can run some low drain things without triggering the compressor to come on but when filling tires the tank slows the filling process if the tank isn’t already full when you start. A 3-way valve(one input from the compressor and two outlets, one to the tank and one straight to your to the supply QD can fix that). You just have to remember how you have it switched when driving and add a second check valve to the tank output.

 

So it’d be better to run a 3 way valve for filling tires straight from the compressor, and use the tank for a locker?

 

That’s a good example. Something like air bags or bike tires would be another but basically any small volume use allows a quiet tank application instead of or to augment a compressor. A compressor alone could do both so many opt to do without since they do take up space somewhere. Tanks just offer that volume of instant pressure without the noise or current draw.