Negative switching

[runningman]

Hi guys, ive done heaps of reading different electrical topics, from not working spotties, uhf installs, etc etc but am still confused about the hilux's negative switching. What is it exactly thats different to pre 05 hilux as i did plenty of custom electricsl on my old hilux.
What wxactly is negative switching?
Thanks

[Steveyb]

Hey runningman,

negative switching is when the negative/ground side a of load is switched in/out in order for the load to work.

The switch is on the negative side of the supply for the load

Hope this helps

[runningman]

So if i wanted a manual on/off switch for, say a uhf radio (lets say i want ANOTHER switch for the radio, crazy i know but only example i can think off) i would put the swutch on the negative /earth wire rather than than cut it into the positive wire?
What benefit does this return?

[Steveyb]

Your idea is correct, however in that circumstance the switch would almost certainly do nothing. The reason why is because you would also have another parallel negative path through the coax shield or the mounting of the radio itself (most likely both) and therefore you would have your return path in conventional terms and the radio would still work.

there are a few advantages in it (and some seasoned auto sparkys could chime in here....)
one being that, you can supply several loads with one positive feed and just have each ground switched out (provided you don't want/need segregated protection for each circuit on the positive side)

[runningman]

I get half what ur saying! Lol
I think more googling will be in order to get my positive switching mind around to this new method!
Thanks for help so far guys

[ng_newbie]

Saves on time and $$$s as you can have less cabling

[LUX666]

Mate,

The Hilux is not exactly negative switching, it is all normal as per previous vehicles, the negative switching that everyone talks about is actually when you tap into the lights to pick up the High beam wire, this is where is all becomes confusing, had me stuffed for a few days, Toyota, and many others, use a polarity changing system, where a wire which is positive on high beam actually reverts back to negative on low beam and neutral when off. There is a great diagram on this site that points out which wire to hook into.
Everything else in the vehicle, I'm referring to added accessories here, wires the same as always, do not switch the negative it can be a very dangerous practice.

Hope this helps clarify

Cheers

John

[bansheebuzz]

Mate,

The Hilux is not exactly negative switching, it is all normal as per previous vehicles, the negative switching that everyone talks about is actually when you tap into the lights to pick up the High beam wire, this is where is all becomes confusing, had me stuffed for a few days, Toyota, and many others, use a polarity changing system, where a wire which is positive on high beam actually reverts back to negative on low beam and neutral when off. There is a great diagram on this site that points out which wire to hook into.
Everything else in the vehicle, I'm referring to added accessories here, wires the same as always, do not switch the negative it can be a very dangerous practice.

Hope this helps clarify

Cheers

John

The hilux is negative switching, it has constant power supply to the headlights and the dipper switch switches the ground for the high and low beams. Hilux's have always had negative switching headlights thou the system has changed slightly over the years. there is nothing wrong with switching the negative, stating it is dangerous is completely incorrect because if the system is done correctly there is no difference to the integrity of the system. I will wire some items negative switched and some positively switched, it all depends on the items being installed and the most practical way to do the job

[ng_newbie]

+1 for Bansheebuzz

Maintaining polarity should only be considered "good form", it is a standard that some people choose to ignore in their haste.

We are talking about 12v, 4AMPs (Apporx.) not very dangerous !!!

Unless you like to suck on the terminators

[Moiv]

As far as I know runningman, it's only the headlights that are negatively switched.
Anything that you put in you can switch the normal way.

[Steveyb]

I think ol mates thinking on being dangerous is born from the land of low voltage wiring where the standards dictate that no neutral is to be switched (except pendants which are both neutral and activitie) a switched neutral is just a silent killer

[aandy]

My 2011 facelift Hilux does NOT have neg switching headlights, this may have changed when we got the "auto" headlights.

[boxhead55]

Yep they sure do. They have not changed.
Nor is the 2014 facelift still neg switching but only for wad lights and computer devices.
This is because transistors can switch an earth easier than a positive.

[boxhead55]

Auto headlights run through a sub computer which switches earths via transistors

[aandy]

Interesting.. I just went and had another look,

Into the headlight plug there are 3 wires

white with black stripe
black with white stripe
red/yellow

All three wires are 0V to earth with headlights off, ignition in all positions.
with headlight on there is 12V between the black/white stripe and earth
with high beam on there is 12V between red/yellow and earth
there is always 0V and continuity between white/black stripe and earth (i.e. it is the earth)

This sure looks like positive switching, at least by the time it makes it to the headlight plug.

Although electrically savvy, I am not an auto electrician, I work in the world of insulated neutral 3 phase on ships.
this may be a terminology thing

[runningman]

Just gets more interesting! Looks like for all intents and purposes, if nothing to do with lights, wiring is the same as pre05 hiluxs, good news to me! Thanks fellas, really appreciate the input from all

[martynvella]

Interesting.. I just went and had another look,

Into the headlight plug there are 3 wires

white with black stripe
black with white stripe
red/yellow

All three wires are 0V to earth with headlights off, ignition in all positions.
with headlight on there is 12V between the black/white stripe and earth
with high beam on there is 12V between red/yellow and earth
there is always 0V and continuity between white/black stripe and earth (i.e. it is the earth)

This sure looks like positive switching, at least by the time it makes it to the headlight plug.

Although electrically savvy, I am not an auto electrician, I work in the world of insulated neutral 3 phase on ships.
this may be a terminology thing

It depends where the wires are on the headlight globe, the positive reading that you are getting could be feedback through the element not alight.

[boxhead55]

Here is the wiring diagram again see one earth in 2 out for headlights


Now there will be a positive going to the switch for the park light circuit


Your auto position on the stick sends a earth (on signal) to the sola computer which is under the dash sensor.
That sensor computer supplies the earth outputs to the headlights and positive out to the park lights when it is in the auto position

[aandy]

According to that first diagram, I should have a constant 12V to the light plug( at "3"), i do not.

With both plugs removed from globes, Black with white stripe gets 12v when headlights are switched on, red/yellow gets 12v when high beam is switched on, the other wire is always earthed.

The red/yellow is actually where i tapped in for switching power (86) for my light bar relay, and yes this still works with both globes disconnected. This would not work according to that first diagram.


something fishy

[martynvella]

God, I might have to put my bonnet up and have a look now, something I don't like to do. The whole idea behind buying a new hilux was so I didn't have to work on it after over 35 years in the trade I am over it.