ARB Headlight Loom - strange workings

Hi Peter

When we have the lights on normal, both high and low beam are on, with the outer light in high beam mode. When we then switch to high beam (by pushing the stalk forward), we just get the single (outer) headlight.
on low beam.

Tempers are becoming frayed : )

Thanks

Jack

The loom is the standard loom sold by ARB, which they say is fine for use on an 80 Series. There is reference to 80n series in the instructions. We have followed these things to the absolute letter, but get this result.

Jack

Hi Jack.
The description you are giving says to me the loom is for a positive switching vehicle and not negative switching like the Cruiser.

Your ARB loom will be switching on high beam when the voltage on the high beam pin is high voltage (+ve 12V or thereabouts). That is it is expecting positive switching.

The Cruiser uses negative switching. The common pin is high voltage (+ve) and NOT low voltage (-ve).

This means on low beam the high beam pin is high which is telling the loom to switch on high beams. On high beam the high beam pin is low which is telling the loom to switch on low beams.
Have a look at this link from LCOOL which describes 80 series headlight wiring.

http://www.lcool.org/technical/80_series/lights/80wiring.html

Probably the easiest way to fix this is swap over the high and low beam switching pins (where it connects to the original loom) on the ARB loom.

Cheers,
Peter.

That did the trick.
So much for the 'any goose can do this'. This goose couldn't without your help.
Thanks

Jack

Your welcome mate.

Happy to be of assistance.

Unfortunately the Cruiser is a little unusual with negative switching on the headlights. I discovered this a while back when playing around with the loom on my 75 series.

If you buzz out the pins with a multimeter, you will at first think the pins are all back to front until you work out it is actually using negative switching.

Cheers,
Peter.

Jack,

You have failed to deduce the obvious...you are NOT a goose!

At least according to ARB.

Duncs

Thanks Duncs ... but I won't shop that around for a second opinion.

Cheers
Jack

Hello Jack, I have a Tropy 2000 model, in the back they have a tiny interior light thats useless, I decided to run some LED strip lites of the original switching. Well when I test the switch (with a test lite) I discover both sides of the switch are positive mmmm scratch head may times, re test same result mmm scratch head, think about it for a while and operate switch and note via test lite that now one side is neg the othewr pos. and lite is on.....Therefore when lite is off there is power to both sides of the switch, when you "turn" the light ON you now have pos. & neg. to the switch
WHY would they do that????

regards..............................Jeff

Hi Jeff:

I have no idea why many things happen. My son has just fitted out a mate's car with LED lights, so I will ask him on the weekend if he calls by.

Sorry I cannot be more helpful.

Cheers
jack

Hi Jeff.

I don't know why Toyota use negative switching but they do.

The reason you see positive on both sides of the switch when the lights are off is because of negative switching.

Jack hit this very problem with his loom. See above discussion.

With negative switching, when both sides of a circuit are high (+ve 12V) then there is no current flow and the device (headlight, interior light, LED, etc) is "off".

Now comes the negative switching bit. When the device is to be turned on, the voltage on one side is held low (-ve) while the other side remains high, a circuit is formed, current flows and the device turns on.

It requires a bit of reverse thinking to understand but it works.

Cheers,
Peter.

Yeah thanks Pete
I understand the issue now but still think it's a crazy way to do it

Regards.......................Jeff