Wiring Nightmare (1 Viewer)

[Joe45]

HJ45 Electrical issues:


Added new rear and front turn signals/lights.

Rear, after wiring, started to blink both lights when right turn signal engaged.

I disconnected the rear lights to sort out the wiring again, but now can’t tell what’s what as far as turn or hazards because when I engage either the right or left turn signal, both flash. This happens using the circuit tester as well as on the instrument cluster indicators.

I pulled the wiring harness out to under the right side door. Removed the wound tape and found a whole bunch of splices with different color wires, etc. Total mess!!!

I traced the spliced wires wires until they came to what seems to be an undisturbed area of the harness just behind the cab.

Here is what I found by sitting in the cruiser and engaging the signals, brakes, etc. while using a circuit tester (the color schemes below are from what seem to be the original wires at the end of all the splices):

White/Black Strip: Nothing
Green/Yellow Stripe: Blinks with both turn signals and hazard switch.
Red/Blue Stripe: Reverse
Green: Blinks with both turn signals and hazard switch.
Green/Black Stripe: Blinks with both turn signals and hazard switch.
Green/White Stripe: Brakes: lights up dimply when ignition is turned to on, bright when brakes applied.


Seems like its all there: wires for brakes, left, right, hazard, reverse: not sure about the nighttime one though. But can’t figure out left or right turn signal wires.

Pressing the brake pedal now also makes the E-Brake light come on.

I have looked for a wiring diagram but:

I can’t find one for a 1980 HJ45. Did find one for an HJ47, but don’t know if that would work.
I don’t understand the diagram. Seems like a jumble. I don’t see any listings of wire color, gauge, etc.

For now, if anyone knows which wires are for what, I’d appreciate some help. I can then splice on wire from that point back and at least have it working until I can rewire it properly.

The issue is knowing which wires are for left and right turn signals, and which for hazards.

Also, the brake lights came with black wires (ground) and the rest are yellow wires with one red one. I imagine the red one is for the brakes.

The brake lights have a weird bulb setup, with a small bulb and a big bulb for the brakes. Is the small bulb supposed to be on when the lights come on, with the large one engaging when brakes are applied?


This is my daily driver right now and I’m looking for work, so am stuck without a vehicle until I can resolve this.

Thanks!!!

 

[Joe45]

And here are a couple of pictures of what I found when unwrapping the wire harness:

 

[45Dougal]

This is the first diagram I used - I scribbled some colours and notes on it. Maybe that helps?

I'm pretty sure that you've got a bad ground at one of your turn signals - you can find which one by removing each bulb in turn - eventually the coupling between the two sides will go away.

 

[Joe45]

This is the first diagram I used - I scribbled some colours and notes on it. Maybe that helps?

View attachment 3465274
I'm pretty sure that you've got a bad ground at one of your turn signals - you can find which one by removing each bulb in turn - eventually the coupling between the two sides will go away.

Thank you. I appreciate it.
However... it's like looking at alien writing to me. I can't make heads or tails out of that. I see the labels, but it seems convoluted. I can't understand why they don't just draw it out like the wires go; like on a simplified diagram of the vehicle.

 

[Joe45]

Is there any way to identify the wire by the color?

• White/Black Stripe:
• Green/Yellow Stripe:
• Red/Blue Stripe: Reverse
• Green:
• Green/Black Stripe:
• Green/White Stripe: Brakes

 

[charliemeyer007]

Well maybe someday someone will draw it up in something like AutoCAD. Would be sweet to turn on the light layer and be able to Bold or Blink the red wire with the white stripe and follow its path in the rig. I'm not holding my breath tho.

 

[Joe45]

Well maybe someday someone will draw it up in something like AutoCAD. Would be sweet to turn on the light layer and be able to Bold or Blink the red wire with the white stripe and follow its path in the rig. I'm not holding my breath tho.

That would be cool indeed!
When I rewire my HJ, I am seriously considering drawing up a simplified top view of it with the wires going along where they truly go. Maybe in color, so a red wire with a yellow stripe will show as a thick red line with a thinner yellow line in the middle. I can do this in Illustrator and even do in as layers.
That may be a cool project to do, because man, the technical drawings are a nightmare for me. I can't figure out what the hell is what-mainly because it's drawn in a way that is not easily understood-at least for me.

 

[45Dougal]

That would be cool indeed!
When I rewire my HJ, I am seriously considering drawing up a simplified top view of it with the wires going along where they truly go. Maybe in color, so a red wire with a yellow stripe will show as a thick red line with a thinner yellow line in the middle. I can do this in Illustrator and even do in as layers.
That may be a cool project to do, because man, the technical drawings are a nightmare for me. I can't figure out what the hell is what-mainly because it's drawn in a way that is not easily understood-at least for me.

The closest diagram to what you describe that I know of is the Haynes manual diagram.
Personally I prefer the toyota original because it has more detailed information, although it isn't colour coded and is also not realistic in layout or connectors.
Maybe my perception is skewed by a doctorate in electronic engineering though tbf.

 

[South Texas 97]

@Coolerman is your friend here.
I had a similar issue with my 76 FJ40, wires looked almost exactly like yours, not sure if chewed or fried.
Traced them all the way to the front bulkhead where there was two 4 pin connectors and replaced the entire rear harness,

Bought bulk wire with the correct matching colors from these guys Harley Stripe Automotive Wire - 540 Colors Available - Custom Len - https://4rcustomswire.com/
16 gauge wire is what I used to replace mine, all the way to the tail light assembly and some additional plugs (sumitomo waterproof connectors)
although other types of connectors work as well.

There is a guide as to the wire size for the different circuits, here.

Coolerman's web site has a list of many Landcruiser makes and years. Follow the "link to wiring schematics" for the list. Look for the
1975-1980_Chassis_Body.pdf this has your HJ45 diagram.

He also has most likely the connectors you will need.

The diagrams are schematics - there is another type of diagram which shows the placement of the harness and connectors but I don't recall the name of those.
Biggest thing is take your time and take notes and pictures.

 

[AKPoser]

I thought this diagram was helpful, but is for 72-73 model fj40. Not sure how different it would be from your HJ?

 

[45Dougal]

Is there any way to identify the wire by the color?

• White/Black Stripe:
• Green/Yellow Stripe:
• Red/Blue Stripe: Reverse
• Green:
• Green/Black Stripe:
• Green/White Stripe: Brakes

Yes it's written on the diagram.


WB = White with black Stripe (Ground)
GY = Green with yellow stripe (RH turn)
GB = Green with black stripe ((LH turn)
G = Green (tail light)

 

[Joe45]

Yes it's written on the diagram.


WB = White with black Stripe (Ground)
GY = Green with yellow stripe (RH turn)
GB = Green with black stripe ((LH turn)
G = Green (tail light)

I missed that.
Thank you!!!

The white with black stripe wire was cut short and left unconnected, so that may be an issue right there.

I'm just going to use whatever color wire available for now to get going. Once I am ready for the resto/mod with a working garage, I will order all the correct wires.

Again, THANK YOU!

 

[Joe45]

@Coolerman is your friend here.
I had a similar issue with my 76 FJ40, wires looked almost exactly like yours, not sure if chewed or fried.
Traced them all the way to the front bulkhead where there was two 4 pin connectors and replaced the entire rear harness,

Bought bulk wire with the correct matching colors from these guys Harley Stripe Automotive Wire - 540 Colors Available - Custom Len - https://4rcustomswire.com/
16 gauge wire is what I used to replace mine, all the way to the tail light assembly and some additional plugs (sumitomo waterproof connectors)
although other types of connectors work as well.

There is a guide as to the wire size for the different circuits, here.

Coolerman's web site has a list of many Landcruiser makes and years. Follow the "link to wiring schematics" for the list. Look for the
1975-1980_Chassis_Body.pdf this has your HJ45 diagram.

He also has most likely the connectors you will need.

The diagrams are schematics - there is another type of diagram which shows the placement of the harness and connectors but I don't recall the name of those.
Biggest thing is take your time and take notes and pictures.

Thanks again!
I'm just going to use whatever color wire available for now to get going, and then do a proper rewiring later when I have the garage.

 

[Joe45]

The closest diagram to what you describe that I know of is the Haynes manual diagram.
Personally I prefer the toyota original because it has more detailed information, although it isn't colour coded and is also not realistic in layout or connectors.
Maybe my perception is skewed by a doctorate in electronic engineering though tbf.

Indeed! It's pretty neat that you can read and understand that diagram. With some time and studying, and guidance, I'm sure I could learn to understand it---it's just that I have way too many things going on. Sometimes it's better to focus on one's skills and talents/gifts, and outsource the things outside that realm.

 

[Joe45]

This is the first diagram I used - I scribbled some colours and notes on it. Maybe that helps?

View attachment 3465274
I'm pretty sure that you've got a bad ground at one of your turn signals - you can find which one by removing each bulb in turn - eventually the coupling between the two sides will go away.

Question:

Does the white wire with black stripe get connected to the frame, or to each negative wire on the lights? I still can't make it out from the diagram. This wire had been cut at the point where all the other wires were cut, but not attached to, so it was hidden under the loom/harness wrap.

I am thinking maybe this is the "bad ground" you suggested. Hopefully it will resolve things, as the taillights were grounded to a bolt on the chassis.

 

[45Dougal]

Question:

Does the white wire with black stripe get connected to the frame, or to each negative wire on the lights? I still can't make it out from the diagram. This wire had been cut at the point where all the other wires were cut, but not attached to, so it was hidden under the loom/harness wrap.

I am thinking maybe this is the "bad ground" you suggested. Hopefully it will resolve things, as the taillights were grounded to a bolt on the chassis.

Both /all.
Normally the lights are grounded via that ground wire which then goes back up to the front of the truck to an established ground point near the battery, but quite often the rear lights just end up grounded via the mounting screws so don't actually need that wire.

When you remove the screws though, you then lose the ground.
Reinstate the wire, or just connect a good wire from each light housing to a solid contact on the chassis

 

[Joe45]

Both /all.
Normally the lights are grounded via that ground wire which then goes back up to the front of the truck to an established ground point near the battery, but quite often the rear lights just end up grounded via the mounting screws so don't actually need that wire.

When you remove the screws though, you then lose the ground.
Reinstate the wire, or just connect a good wire from each light housing to a solid contact on the chassis

Great!
Will do!
Thank you!

 

[South Texas 97]

I ran an extra ground to each of the tail light housings - you can see it here and ran that ground (White with Black stripe) up to the ground on the frame under the pax seat.

 

[Joe45]

I ran an extra ground to each of the tail light housings - you can see it here and ran that ground (White with Black stripe) up to the ground on the frame under the pax seat.

Good idea! Thanks!
I just purchased some wire. I'll work on it tomorrow and let y'all know the results asap.

 

[pb4ugo]

Thanks again!
I'm just going to use whatever color wire available for now to get going, and then do a proper rewiring later when I have the garage.

If you're going to do that, use different color wires for each application. You might consider getting a trailer wiring kit. It comes in a grouping of 4 or 5 different wires with separate color coded wires. Each color is designated for its use. Rt, Lt, brake etc. If the lights act strangely like your turn signal wires both flashing is probably a grd issue. Turn signals and flashers use the same wire.