greaseman

I am almost done with my OBA. I used my A/C pump for the compressor. My question is..... How do I wire up the screw in pressure switch that goes in my manifold. When I am done I will post pics and a how-to thread. So far it works great

Brian71583

Your question is pretty vague but I'll assume you are using just a basic two prong pressure switch. Your A/C compressor is grounded through the body so mount a rocker switch inside the Jeep somewhere and run a single positive line to it. Then run the positive out of the rocker switch to the pressure switch. Then back out of the pressure switch to the single wire going into your a/c clutch.

The rocker switch will act as a master switch, if its not on, the OBA wont come on. Then the pressure switch comes into play. If the rocker is on, but pressure in the system it wont come one either.... Rocker is on, no pressure... compressor turns on. This way you can kill the compressor. If you dont mount a rocker and you blow an airline or something the compressor wont shut off until you disconnect it.

I am also in the process of doing on A/C OBA system but mine is quite complex. I plumb the air system on new Mack trucks so I said go big or go home.

greaseman

That is excactly what I am using. I have a three prong rocker installed just not wired yet. Thanks for your help

greaseman

Got it wired up and plumbed.....now when it's done with pressure it blows back out the oiler line. Do I need to put a one way vavle?

Brian71583

Yes, check valve before any manifold/tank you have plumbed in.

greaseman

Thanks for your help. I really appreciate it. I will post up pics when its done and you can tell me how it looks

greaseman

Ran the compressor...left it build pressure and it shut off at pressure
rate. bled it out and it kicked back on. So I left the jeep run while I put zip ties on. Then the engine shut down. I had NO power anywhere. I found the 60 amp fuse under the hood was blown and the rocker was hot. Any Ideas?

Brian71583

Did you install a check valve? The a/c system is more powerful than the 100 or so psi that you'd be doin but without the check valve maybe it's putting extra stress on the compressor/clutch

Is there a fuse between your rocker feed and the clutch anywhere... Shouldn't need anything high amp, but put one in and see if that blows first next time

Maybe bad a/c clutch????

greaseman

maybe i wired the rocker wrong.
black-gound
acc-pump
power-batt

someone said about puttin a 3 prong 12v relay in after the rocker?
pump works great wired straight to battery

Brian71583

Everything I read says the a/c clutch doesn't draw much at all so a relay isnt necessary. Also if you blew a 60 amp fuse... A 30 amp relay would blow too.

ProudXjOwner

X2 My fuse is a 15a and has never blown.

greaseman

I'll retrace all my wiring. It is possible I have the power and acc swapped. Or doesn't that matter?

greaseman

I retraced the wiring. And I had the 2 reversed. It runs fine now. So now all I have to do is clean out the back and mount the tank securely.

billulsund

I would reccomend powering the switch from ignition power and not battery power. If you get power from the battery and you accidently leave the switch on it will kill your battery.

Monster Mopar

Better yet, find a power source that is only on when the key is in the run or acc. position. That way the clutch won't be engaged when you try to start the engine. Reducing overall torque needed to turn the engine over and reserving as much power as possible for the starter.