New Loom confusion

[ferrit]

Gday!

Building a new loom for my headlights on my hilux- using the loom off the 80 series owners online site...

And ive got a problem!

using the driver side headlight plug as a trigger wires, and using the new loom on the drivers side, and the old loom on the passenger, everything works, high, low, both work fine.

Plug the new loom into the passenger side, and i get no headlight switching- they will switch on and off, but i cant get high or low beam.

What have i done wrong?

[chimpboy]

Morning.

Are you hooking the passenger side up to the driver's side, ie triggering from the drivers side plug? Or are you triggering it separately from the passenger side plug?

[ferrit]

hooking the passenger side to the drivers side- saves on relays and wiring....

[RoldIT]

Are cruisers negative switched headlights?

If so, has the loom been built/modified to suit?

[drivesafe]

Hi RoldIT, all the older Toyotas that I have worked on were, not sure about the latest ones.

Cheers.

[ferrit]

yeah- the cruisers and hilux's are all negative switched... the new loom is modified to this according to this site here...

http://www.safari4x4.com.au/80scool/tec ... iring.html

I get full power to both sides of my new loom, so why doesnt it work properly with both sides of the new loom in, but does with the old passenger side plug on the light?

[-Scott-]

Plug the new loom into the passenger side, and i get no headlight switching- they will switch on and off, but i cant get high or low beam.

I'm a little confused by what you mean here. If you can't get high or low beam, what's switching on and off? Or do your headlights come on, but not change as you switch your dip switch?

Scott

[gtir300]

I have just built this very loom for my 80 series, altho I just followed the proven plan.

When i first plugged it all up the 4 globes came on and the dip switch did nothing, I had just connected it up wrong to the passenger plug, swapped the cables round and it all worked ok.

I am by no means an auto electric expert, but from looking at the plans given for this, the orginal setup is for negative switching, but the add on loom diagram now adds power to two of the three globe connectors i.e. one common earth. This had me stumped when I was wiring it all up, but then I didnt have lots of coloured cable Or I just dont understand electrics........more likely

[ferrit]

they wont change when i plug the new loom in scott...

They change fine when the old looms on the passenger side, but when you switch it to the new loom on that side, all you can get is low...

[spannercrab]

I had a very similar problem on a '85 BJ 'cruiser ... there is something very odd about the switching on Tojo headlights. Something to do with the way they were grounded if I remember correctly.

I can't recall what it was off the top (sorry - I know that's not much of a help), but I tracked it back through the OEM wiring diagram which eventually solved my problem.

[Bluey]

ferrit
used the same site when i made my headlight loom. used on a hilux for 2 years, then middy cruiser for another 2 years, although had to lengthen wires to go from headlight to headlight.

i don't think you have a ground on the passenger side new loom connector, and therefore globes won't turn on

1. it doesn't matter if you plug the sense cable to old loom on drivers or passenger side. choose easiest side for you
2. loom is converting vehicle wiring from a negative switch headlight to a positive switch headlight, thus the need for diode and dropping resistor.
3. measure with a multimeter (referenced to ground or chassis) all three pins on your new loom, both sides (drivers and passenger), and headlights off, low beam and high beam on. should get same volts on each connector for each lights on position
4. if all the above checks then make sure that the common pin of the H4 globe is sufficiently grounded, plug in new loom to headlights and should work fine

hope this helps, if not just fire away and try again

[ferrit]

the two globes are physically joined together in the new loom by a common earth wire which goes back to the bolt where the body earths to the battery!

It will RUN both globes on low beam just fine, but without the old loom plugged in, it wont switch- theres no sound at all from under the bonnet....

[-Scott-]

the two globes are physically joined together in the new loom by a common earth wire which goes back to the bolt where the body earths to the battery!

It will RUN both globes on low beam just fine, but without the old loom plugged in, it wont switch- theres no sound at all from under the bonnet....

OK, I can't come up with too much here. Looking at the "modified" diagram, the low beam relay will stay energised until the high beam relay switches. But I can't guess why.

When you have the old loom plugged in, do your new relays switch?

Scott

[-Scott-]

Had another look at both diagrams - I'm not sure this is the problem, but it may be a contributor:

As somebody else pointed out, the original wiring uses negative switching while the modified wiring uses the original negative switching to switch the relays, which positive switch the globes. This means the voltages on the various H4 globe pins change from one configuration to the other.

H4 globes have two filaments with one common pin. From memory, viewed from the rear (and rendered in ASCII ) they are:

High beam --> | _ | <-- Common (Low beam in the middle)

In the original configuration, the common pin has 12V supplied, and the other two are alternately switched to ground.

In the modified configuration, the common pin is connected to ground, and the other two are alternately supplied +12V through the relays.

Do you have the pins wired correctly? I can't work out how it would cause the problem you're experiencing, but let's rule out as much as possible.

Cheers,

Scott

[ferrit]

i'll check em in the morning... cant be frigged going out to the truck at the moment!

When the old loom is plugged in on the passenger side... and the new loom is on the drivers side, the lights work as they should- high and low beam both work.

When the old loom is disconected, the low beam works, but wont switch to high.

[-Scott-]

When the old loom is plugged in on the passenger side... and the new loom is on the drivers side, the lights work as they should- high and low beam both work.

Yep! Got that! But AFAIK, they worked before you started, so I'm trying to figure out if it's the old wiring doing the switching, or the new.

I'm guessing it's the new wiring, or the driver's side lights wouldn't be switching - but it would be nice to confirm that the new relays are switching on and off properly.

If we can't work out what's not working, lets start by confirming what is.

New test: unplug the passenger's side, so NOTHING is connected on that side. Does the driver's side still switch properly?

Scott

[ferrit]

Passenger side completely unplugged, drivers side wont switch properly

[-Scott-]

OK - so we've possibly got a relay earthing through a headlight filament on the passenger's side.

With passenger side plugged in to OLD loom, is there a significant difference between the brightness of the lights?

Scott

[ferrit]

theres not a significant difference in brightness... but it is notibly duller on the passenger side...

Could be i need to use the passenger side plug as my switching wire source?

[-Scott-]

It shouldn't matter which side you pick up from.

I think the pink/purple connection in the modified diagram has a fault. When your passenger's globe is installed, and high beam is on, the relays are energised - but remove the globe and the relays turn off. This implies the relay is earthing through that globe.

But I can't see how you could have that connection, without the connection to earth through the hi/low switch. Did the Hilux originally have it's own high beam relay?

Another silly question - does the high beam dash indicator work as you expect?

Scott

[ferrit]

Dash indicator comes on fine- when the bloody passenger side plug is connected! :S

Wonder if a set of 27ohm 5w resistors jammed into the old plug to complete the circuit would fix the bloody problem!

[-Scott-]

Looking at the "modified" diagram, I presume you have them connected to the original headlight plug?

Swap the "brown" and "pink" wires over.

Scott

[gtir300]

The resistor is for lowering the current through the stalk switch to stop it burning out in time, so it should work with out.

I did have some fun with mine when I started to install it, i found out that as the Toyota is -ve switched and the modified loom changes this to positive switch, I only had to plug the new loom in to the passenger side plug outer terminals (the thicker wires) as the globes are then getting two separate +12volts with the common earth coming off the middle connector to the car body adjacent the light.......sorry cant explain it better than that.

I believe the middle thinner wire for the modified circuit is for the Autolight off feature (as well as completing the switch circuit properly rather than through the body), and hence that is why I had to wire this in to get this feature to work.

Just telling it how I found out!

Just another point though, this new loom does state that its for passenger side connection. I searched the web and found www.sleaoffroad.com in the USA that make this very loom for the 80 series 'cruiser (LHD obviously) and their loom was for connection ONLY to the drivers side i.e. the same plug! I didnt think it would make a difference but might be worth considering.

As Hilux is single light units, you will only need 2no relays (5pin - with two outlets[pin 87's]) with each relay being low and other being high beam.

best of luck

[ferrit]

awwww.... but that means pulling the washer bottle out again

theres practically nothing connected on the passenger side- the plumbing for the air cleaners all sitting on the shed floor apart from intake to canister!

[-Scott-]

The resistor is for lowering the current through the stalk switch to stop it burning out in time, so it should work with out.

No.

The resistor is there to reduce the voltage drop across the high beam indicator light when high beam is on. When low beam is on there should be no current flowing through the resistor, as one end is grounded by the switch and the other end is grounded by the high beam filament.

In the original circuit, the high beam indicator is fed 12V via the low beam filament.

I don't know what will happen to your indicator light if you omit the resistor and wire it directly.

Scott

[Bluey]

fault finding is so much easier in person
if you have your loom connected to drivers side, and old loom to passenger side, then: passenger side lamps turned on/off dirrectly from old (original) loom, drivers side lamps turned on/off from old (original) loom activated the new loom and relays that do switching of lamps. if in this setup it all works, but when plug new loom to both sides and it stops working then i would think it is wiring mistake from drivers side to passenger side of the loom. also check connections, think hiluxs have sealed headlights, and the prongs for H4 connections can easily bend out of the way and thus don't connect properly to the loom


how it works from the wiring diagram: (hope this helps in some way)

of three new relays, ignore top one for a hilux
middle one is high beam relay
bottom one is low beam relay

red connections are hardwired 12v from battery, thru fuses to low beam relay (new) and high beam relay (new) - common on contact of relay

factory headlight relay (and hilux will have one of these (99.9% sure)) feeds 12v to one side of coil of low beam relay and high beam relay when headlights turned on. other side of coil is switched to ground to turn on the relay as below

low beam is brown connection, thru R1 and D1, turns on low beam relay, and then yellow connection transfers 12v to low beam lamps. also turns OFF high beam indicator because GND (or 0v) either side of indicator lamp

high beam is pink connection, turns on high beam relay, and red connection feeds 12v to high beam lamps. 12v also goes back thru dark purple to R1 (but not D1 as it is now reverse biased), out to high beam indicator lamp which now turns on.

obviously common of both drivers and passenger sides lamps is black coonection to ground point