Outer Limits 4x4 Board

So here's a weird one....
Over a year ago I fitted an ARB twin motor air compressor. It came with its own switching loom, and for power it's wired to a heavy 12v fused feed direct from the battery. Operates via a one gallon tank and pressure switch.

It's run like a gem for all this time, inflating 37's with ease, running air freespool etc.

On the weekend the switching loom decided to fry itself. Once or twice the compressor started running slow to the point where it stopped. Made me initially think it was a thermal cut out, but then it would just shut the compressor off immediately, no?

Next thing, smoke, and fried loom. Pulled all plugs out to save any further issue.

The loom is four wires, two redundant in my case, I believe these are for if/when you use the compressor for air lockers?
The black/earth wire is what's cooked.

I'm stumped. I know the compressor has a relay for each side, did the relay poop out and earth itself through the switching circuit?

Btw, spoke to ARB today, they are also at a loss to explain, but will replace the loom no worries.

Any ideas anyone?

Hot wire the motor to ensure it hasn't seized or shorted out.
Both can make current go very high and burn a lead.
So can a faulty connection where heat builds up at that point and away it goes.

ive bought the old school slugger and the newer compressor all ARB..brand

but not the twin compressor.. yet..

ive always had the twin terminals melt on mine, old school and the present one..
made them fix it for free.....

usual......ooh that's un common..

well I'll bet when or if I go the arb twin one ill have the same issues.

more keen on THE BOSS..
I reckon because I run a 5gallon tank, and rear locker..
the heat running through the plug wasn't designed for full time use..

I think they under engineer some of the gear..
and don't think some people will actually use their compressors a lot..

and the plugs and possibly wiring aren't up to scratch.

I would have thought the twin compressor would have all those issues sorted by now...

The only time i've had a problem with my ARB twin was when the battery voltage was low.

How ever i did run heavy cable as close to the compressor as possable.

Hamo

A lot of guys I know have trouble with the ARB compressors and their wiring, most have hard wired to remove the plug at the compressor since it is only rated to like 15-20A or something low. Mine melted causing the compressor to slow and run crap, other issue of random cutting out turned out to be a faulty thermal cut out.

GUtripper wrote: The black/earth wire is what's cooked.

you should never be able to fry a cable. the fuse should have blown well before that. the only way a cable will fry is if its undersized or has a bad connection which heats it up.

tweak'e wrote:

GUtripper wrote: The black/earth wire is what's cooked.

you should never be able to fry a cable. the fuse should have blown well before that. the only way a cable will fry is if its undersized or has a bad connection which heats it up.

That surprised the hell out of me too. Particularly as it cooked the insulation of almost the full length of the earth wire without blowing the fuse.

Have a new switching loom. Next week I'll remove the compressor , bench test it, maybe dismantle the cover and replace the relays just in case, and test the thermal cut out somehow.
Removing multi plugs and soldering joins sounds like a good plan.

The earth wire is cooked you say, insulation fried. Its had a direct positive feed somehow. Its bypassed the fuse.

id be taking it up with arb, and no resolve higher up...
HQ in your state..

something has gone seriously wrong to do that..

we were on port Kembla bluescope doing a major upgrade on one of the boilers..

anyway we were welding up the pressure pipes in position close to the burners and had nothing to earth to..
the paint used is an industrial epoxy, and wasn't keen grinding that shit off
soo I said earth it too the bolt.. on the flanges....................... good idea aye
anyway started welding away.. my mate pipe welder, next minute the electrical cables to the valves melted the insulation

what happened was the current took the least resistance to the weld, and went through the valve solenoid cable and to the weld joint...

soo same is going on with your compressor, your damn lucky the car didn't catch on fire...

shame it didn't she's only a 3ltr patrol

nearly call it a jeep if that happened

Thanks Cruzaa.
And yes, it's a jeep.

You can add a fuse to the earth line aswell for peace of mind, but as tweak'e said, you should never be able to fry the supply cables. The fuse close to the supply source exists to protect the wiring (NOT THE DEVICE! as most people believe)