Adding a 12V rear fog light - where to take a power source (1 Viewer)

[Eurasiaoverland]

I want ultimately to import my BJ60 (General market, 12V) to Europe (UK) and to do that, it needs to have a rear fog light which is independently switchable and has a tell-tale (e.g. light) to show when it's on. I am not sure where to take +12V from inside the vehicle.

Only the European-market 60s got a rear fog light provision and there is no fog light circuitry in my vehicle. I have the entire wiring harness (all sections) out right now and want to add the fog light wiring to the harness so that it is fully integrated and looks factory.

The fog light will be a bolt on external 21W lamp found on Hino trucks which is pretty much identical (uses the same Koito lens) to the factory supplied unit on my UK-delivered Hilux. That will be similarly mounted under the rear bumper.

For waterproof, period-correct connectors, I have these Sumitomo parts, with 6.3 mm blade terminals:

The feed wire will be routed down from the cowl wire, along the floor wire (LH side of the vehicle on my model) to the 'rear floor wire' that runs up behind the very rear of the body. I will ground the light to the existing 6 mm ground bolt in the middle of the rear body.

The switch will be a re-purposed spare rear window defogger switch. This has three terminals, which I assume are a switch in the supply-to-light feed wire, and a common ground. Question - I assume that the integral light is powered by the switched supply circuit, so comes on when power is being fed to the light?

The original dashboard switches (such as the rear window defogger) are supplied by 'cowl wire no.2' (mine is 82132-90A15) which given the ultra low spec of my vehicle, has many redundant connectors.

From left to right, the connectors are (not including the bus connector which links to the main cowl harness):

• H4 button -not used in my car as it has a direct shift type transfer, though all the wiring is present to take a vacuum type (apart from on the transmission harness where I have taken it out).
• Rear window defogger - this is in use.
• Rear window wipers - not used in my model as they were all the swing-out back door variant.
• 12V light for the switch bezel - this is in use.
• Power antenna - this is not in use and was never even an option. The wires are not present on the cowl harness side of the bus connector.
• 12V cigarette lighter socket. This was not in use originally as mine came without a socket (factory blanked off), but I am adding one from an HJ60.

Under the steering column there is a relay panel which has an unused slot for the push-button 4WD VSV relay. I intend to re-purpose this circuit for the fog light, and buy the correct relay to do this (90987-03001).

As I understand, the circuit would then be this:

• There would be one wire running via the current-handling pair of terminals in the relay from the ignition to the fog light, and
• there would be another wire running from the switch to the trigger circuit of the relay.

I'm a bit uncertain about how the trigger circuit would work, and how to be sure that the light bulb in the switch would be powered when the trigger circuit is closed. Would the trigger circuit just run from the ignition to ground via the switch and relay?

Electrics are clearly not my forté so I would appreciate any advice!

Thanks

EO

 

[Eurasiaoverland]

So I have done more investigation but am confused in how the VSV circuit works...

There is a 4 terminal relay
Terminals 1-2 are the solenoid
Terminals 3-4 are the switch in the relay.

Terminal 1 is BW and goes to the blue VSV
Terminal 2 is WB and a ground.
Terminal 3 is B
Terminal 4 is BR and goes to the red VSV

In the H4 switch (I don't have a switch but just tested the female connector) there are 5 wires:

Terminal 1 is G and a 12V with continuity to the adjacent switch bezel bulb
Terminal 2 is Y and goes to the 4WD light on the dashboard
Terminal 3 is WG and a ground
Terminal 4 is B and goes to the relay terminal 3
Terminal 5 is BW and goes to relay terminal 1

I can't find where this circuit draws power from the fusebox, I think I have tried every combination of relay terminals 1, 3 and 4 and switch terminals 1, 4 and 5 with the fuse terminals and none show continuity.

Any help with how I can repurpose this circuit?

Thanks!

 

[sved]

Your 12v comeback from the Dome fuse.
Attached the diagram for you.

 

[Eurasiaoverland]

Your 12v comeback from the Dome fuse.
Attached the diagram for you.
View attachment 3303620

That's great, thank you very much!

By any chance, does your wiring diagram show where the 4WD switch (on a vacuum-shifting transfer case) draws power from?

Thanks again

EO

 

[sved]

Engine fuse

 

[Eurasiaoverland]

That is really very helpful indeed - can now see exactly how the wiring runs and can easily construct the wiring for a fog light. I think I have two options; use the power feed from the ENGINE fuse that previously ran to the H4 switch, or make a new fused circuit in a blank slot in the fuse box specifically for the fog light.

For clarity, Ishould update my previous details on the H4 switch terminals:

Relay:

Terminal 1 is BW and goes to the blue VSV
Terminal 2 is WB and a ground.
Terminal 3 is B
Terminal 4 is BR and goes to the red VSV

In the H4 switch (I don't have a switch but just tested the female connector) there are 5 wires:

Terminal 1 is G and a 12V with continuity to the adjacent switch bezel bulb
Terminal 2 is Y and goes to the ENGINE fuse.
Terminal 3 is WG and a ground
Terminal 4 is B and goes to the relay terminal 3
Terminal 5 is BW and goes to relay terminal 1

Thanks again

EO

 

[Eurasiaoverland]

One last question, where does this wire (red arrow) go to? As I understand, it should be a ground, but the red colour is not usually a ground on these vehicles...

 

[Eurasiaoverland]

So, with a big thank-you to sved, I am planning to wire up the fog lights by partly using the H4 switch circuit:

One thing I have not mentioned - UK regulations require that the fog light can only be switched on when the parking lights or headlights are on.

The H4 switch circuit is good here as it has a bulb feed which I am pretty sure comes from the instrument panel illumination circuit, which is switched through the headlight switch. I will use this, through the fog light switch, to trigger the relay and illuminate the 'ON' light in the fog light switch.

Separately, I will use the H4 switch feed from the ENGINE fuse to power the fog light through the relay.

I will make a small harness between the H4 switch connector and the fog light switch and by doing this, I make the above modifications without cutting a single wire in the original wiring harness. All I then need to add is a wire running from the relay through the cowl harness, floor harness and rear floor harness to a point where it connects to the fog light.

If any competent electrician sees a problem in my plan, I'd be glad to hear it.

EO

 

[sved]

Sorry for the late answer. Out of town until Sunday evening.
I will check the mystery wire in the diagram and report back.
Your diagram looks OK to me.

 

[sved]

As promised.
This time the complete overview.

 

[ToyotaMatt]

I want ultimately to import my BJ60 (General market, 12V) to Europe (UK) and to do that, it needs to have a rear fog light which is independently switchable and has a tell-tale (e.g. light) to show when it's on. I am not sure where to take +12V from inside the vehicle.

Only the European-market 60s got a rear fog light provision and there is no fog light circuitry in my vehicle. I have the entire wiring harness (all sections) out right now and want to add the fog light wiring to the harness so that it is fully integrated and looks factory.

The fog light will be a bolt on external 21W lamp found on Hino trucks which is pretty much identical (uses the same Koito lens) to the factory supplied unit on my UK-delivered Hilux. That will be similarly mounted under the rear bumper.

For waterproof, period-correct connectors, I have these Sumitomo parts, with 6.3 mm blade terminals:

View attachment 3303268

The feed wire will be routed down from the cowl wire, along the floor wire (LH side of the vehicle on my model) to the 'rear floor wire' that runs up behind the very rear of the body. I will ground the light to the existing 6 mm ground bolt in the middle of the rear body.

The switch will be a re-purposed spare rear window defogger switch. This has three terminals, which I assume are a switch in the supply-to-light feed wire, and a common ground. Question - I assume that the integral light is powered by the switched supply circuit, so comes on when power is being fed to the light?

View attachment 3303275

The original dashboard switches (such as the rear window defogger) are supplied by 'cowl wire no.2' (mine is 82132-90A15) which given the ultra low spec of my vehicle, has many redundant connectors.

View attachment 3303283
From left to right, the connectors are (not including the bus connector which links to the main cowl harness):

• H4 button -not used in my car as it has a direct shift type transfer, though all the wiring is present to take a vacuum type (apart from on the transmission harness where I have taken it out).
• Rear window defogger - this is in use.
• Rear window wipers - not used in my model as they were all the swing-out back door variant.
• 12V light for the switch bezel - this is in use.
• Power antenna - this is not in use and was never even an option. The wires are not present on the cowl harness side of the bus connector.
• 12V cigarette lighter socket. This was not in use originally as mine came without a socket (factory blanked off), but I am adding one from an HJ60.

Under the steering column there is a relay panel which has an unused slot for the push-button 4WD VSV relay. I intend to re-purpose this circuit for the fog light, and buy the correct relay to do this (90987-03001).

As I understand, the circuit would then be this:

• There would be one wire running via the current-handling pair of terminals in the relay from the ignition to the fog light, and
• there would be another wire running from the switch to the trigger circuit of the relay.

I'm a bit uncertain about how the trigger circuit would work, and how to be sure that the light bulb in the switch would be powered when the trigger circuit is closed. Would the trigger circuit just run from the ignition to ground via the switch and relay?

Electrics are clearly not my forté so I would appreciate any advice!

Thanks

EO

i have some REAR FOG lamps switches for your BJ60



.

 

[Eurasiaoverland]

As promised.
This time the complete overview.
View attachment 3305256

Again, thanks for sharing these images, really helpful! I would not have guessed that it went to a running light relay in Scandinavian models only (is it standard there for cars to have running lights on at all times? - I remember you could not turn them off in Volvos of the 1980s ). Of course, my ultra basic model does not have this so I will just leave it with its factory grounding.

 

[Eurasiaoverland]

i have some REAR FOG lamps switches for your BJ60



.

As per a separate thread I'm going to re-purpose a spare rear window defogger switch. The correct decal is a light with horizontal beams shining to the right with a 'fog' symbol of a wiggly vertical line (as in your fifth picture) so I'll have a try with the decal below:

 

[ToyotaMatt]

nice !