Hard Wiring of Air Compressor

[stingsprado Lurker Find all posts View Profile Close stingsprado]

G'day all you auto leckies,

I have a old ARB air compressor mounted under the bonnet and this compressor is fitted with a pressure control switch. What I want to do is hard wire it with a switch in the cab so that I can start it up from inside the cab but have the pressure switch turn it off once it has reached it's max pressure. I have just replaced my Cibie Turini's with a pair of Hella Rallye 4000's and they came with a wiring instructions and these have given me a bit of a clue.
Now I know that I will need a relay but do I need a fuse between the the power source for the in cab switch and the # 86 terminal on the relay?. The pressure switch will be in the loop between the cab switch and terminal #86.
Also when I got the relay and the in cab switch I could only get a switch that illuminates once on. It has 3 poles on the back EARTH, LOAD and SUPPLY and I am struggling with what goes were and how SO IF SOMEONE CAN POST A WIRING DIAGRAM that would be much appreciated.

Thanks
Steve

[damonat Advanced Member Find all posts View Profile Close damonat]

you only need 1 power fusin point.
do this on the power supply wire.
will check if i still have my wiring diagram for the compressor

[waltec Senior Member Find all posts View Profile Close waltec]

Just tap off a fuse in the cab, probably off an ignition source, so you can only run the compressor whilst engine is on. Most larger compressor recommend this due to the high current use. The cigarette lighter would be a good one.

As for wiring up the switch, names are standard electrical terms, Earth is ground or negative, will be many good earth points under dash. Supply is where the power comes from, ie the fuse mentioned above. And load is the device using the power, in this case the relay.

As for wiring up the relay, come from the fuse, (split of the cigarette power), to the supply on the switch, out of the load terminal through to the engine bay into the pressure switch. out of the pressure switch to the control terminal of the relay (86).

As for the compressor wiring, I'd come off the positive terminal off the battery, through an auto reset fuse/breaker (40 or 60A should be fine) then to terminal 30/51 of the relay. out of terminal 87 to the positive input of the compressor. the negative of the compressor needs to be conected to either a good earth point or the negative battery terminal. The earth of the switch and earth of the switch need to be connected to earth points of the car.

Let me know if that doesn't make sense and I'll see if I can knock up a quick drawing.

Matt

[stingsprado Lurker Find all posts View Profile Close stingsprado]

Matt,
Thanks mate your reply was very informative and helped heaps.
I have a dual battery set up and the compressor will be drawing it's power from it. Would it be good idea to supply the power for the switch from the dual battery as well so that I don't have to have the ignition on. A drawing would be great if ya could manage it mate.

Thanks
Steve

[waltec Senior Member Find all posts View Profile Close waltec]

Hi Steve

I have whipped up a quick drawing, not real flash didn't have a decent program, but hopefully you'll get the idea.

No need to get the power for the switch from the 2nd batt just find a constant power fuse under the dash, interior lights should be a good one.



Matt

[stingsprado Lurker Find all posts View Profile Close stingsprado]

Matt,
Gee mate when ya said it's not real flash,you were right you could have used some bloody colour in it for the different wires :lol: :lol: :lol: :lol: .
Thats excellent, not only will it help me but it should benefit a heap of others out there, and best of all I didn't get told off by Team Piggy either, I feel better now.

Thanks
Steve

[VL400 Member Find all posts View Profile Close VL400]

Great diagram waltec, makes it heaps easier for ppl to wire up now

One thing stingsprado, dont forget to include the pressure switch somewhere in that diagram, can be done a couple of different ways but just be sure it only switches the current to turn on/off the relay not the full motor current. Putting it on the wire that goes to pin 86 of the realay would be one way to install it - wire the two pins so its an inline switch.

[waylib Member Find all posts View Profile Close waylib]

I am not wanting to fit a compressor but would like to know if is it possible to use the same wiring diagram to fitand run a 200W inverter. I dont have a dual battery so would want to be able to turn the inverter off from the dash whenever I dont need the power without having to open up the back of the car and turn it off on the unit.

Cheers
Wayne

[damonat Advanced Member Find all posts View Profile Close damonat]

I am not wanting to fit a compressor but would like to know if is it possible to use the same wiring diagram to fitand run a 200W inverter. I dont have a dual battery so would want to be able to turn the inverter off from the dash whenever I dont need the power without having to open up the back of the car and turn it off on the unit.

Cheers
Wayne

yes you could use this diagram.
just be sure to use 6mm wire for 30, 87 and the inverter earth.

[waylib Member Find all posts View Profile Close waylib]

Thanks Damonat. Hopefully will get it sorted this weekend.

Cheers
Wayne