ARB Twin compressor stopped working - Fixed

[nick_the_fish]

Morning all,

As the title says - my ARB twin air compressor has stopped working. I used it to inflate all 4 tyres from deep sand pressure to tar pressure like I have many times over the last few months without a problem. Drove to campsite, went to use the air gun and the compressor wouldn't turn on. I checked the 40 amp fuse and it had blown.

Replaced fuse - still won't turn on.

I noted that if I turn on the headlights the air compressor and ARB diff locker switches don't illuminate - so this leads me to the wiring loom.

Getting out the old multimeter I can see that there is 12v getting to the compressor via the power loom. And there is 12v leaving the compressor into the switching loom connector, although I note that there is kind of a funny set-up where there are 3 wires into the connector on the compressor side, and 2 out on the switch side, with the 12v being in the wire that doesn't have an opposite wire....if that makes sense??? Anyway its how ARB designed it so I assume that isn't the problem.

Anyway I can't find any power at all in the switches. I don't remember their being a fuse in the switching loom, and looking at the wiring diagram from ARB there isn't a fuse shown.

Just wondered if anyone has had a similar problem? Or any ideas on what to check next?

Thanks in advance.

Nick

 

[karl2000]

Just a thought - is it possible that the switches are on the negative wire and that's why you don't see power there?

 

[fbnss]

Is wherever its connected to for the 12v sensing thing ok? i remember having to wire the switches so it wouldnt run without the engine on (or have i made that up?) i remember i wired the light on the switch to the heated seat light.

 

[nick_the_fish]

Just a thought - is it possible that the switches are on the negative wire and that's why you don't see power there?

it's a good thought, but just to be sure I checked every wire on the switch and none of them had 12V in them.

Is wherever its connected to for the 12v sensing thing ok? i remember having to wire the switches so it wouldnt run without the engine on (or have i made that up?) i remember i wired the light on the switch to the heated seat light.

hum, that's actually a really good call. I have it hooked up to the cigarette lighter wire (I've removed the cigarette lighter so the circuit isn't overloaded). Unfortunately the tuck left South Africa this morning en-route to the USA, so I won't be able to check until mid July when I get there. But it would be good to have a list of things to check, so I'll add that to the list.

The other thing I should have done but didn't is to do a continuity test of the wires for the loom connector to the switches to check that the wire didn't burn out when the fuse blew, or that there isn't an inline fuse which I can't see and had forgotten about.

But thanks for the suggestions chaps.

Much appreciated

N

 

[Chris]

MIne packed up in a simila manner and it was the rather cheap relays

 

[nick_the_fish]

Well, I'm rather embraced to write this.... but in the hope that maybe one day it'll help someone else....

Obviously the first thing I checked was the fuses and the earths. They all seem good so I started looking for other issues. After some useful input from you guys, and hours spent thinking, testing, tinkering and more testing I was at a loss.

Then I noticed it, as well as the 2 large earths, the compressor also has a very small earth, which, when inspected, was not making a good contact. a 3 minute job solved the problem, and also got the air horn working again, which shared the same earth.

Hindsight is a wonderful thing an everything, but if only I have looked a bit more carefully during those initial inspections.......