The "Official" FJ25 Wiring Harness Thread (2 Viewers)

[Coolerman]

I could send it to ya?

Sure! Would love to have it to fully document it.

 

[mmcinnis]

Sure! Would love to have it to fully document it.

No problem, will send it asap when i get off the ship. Thanks Mike

 

[Coolerman]

I got the generator harness last week. Excellent condition! Thank you.

 

[Coolerman]

Hey guys,
Long time between updates! Day job got REALLY busy this year! We are just starting to wind down. So back to harness building and working on the FJ25 harness!

After reading about the need to rearrange some of the fusing, I came up with a way to do it easily.

First thing I would do is make the third and fourth fuses on the fuse block, key switched fuses. This would be accomplished by first replacing the turn signal B+ wire on the key switch IG terminal with a 12ga wire and running that from the IG terminal on the key switch to the third center fuse of the fuse block. Next, making a jumper from the center fuse, to the fourth fuse below it, so that fuses three and four are now key switched. Then running a wire from fuse three to the turn signal flasher B+ terminal. That fuses the turn signals separately from the brake light(s) making it easier to trouble shoot.

Then Fuse #4 could be used for the horns and/or reverse lights, or if one preferred just use it for other accessories.

A way to gain yet one more fuse is to use the OEM FJ40 6 circuit fuse block which has three always hot fuses, and three key switched fuses. It will bolt right in to the FJ25.


Gas Tank Sending Unit Fuse Mystery Solved?
I may also have figured out why Toyota fused the gas tank sending unit. This seems to make no sense to anyone until you look at where the sending unit gets its power. It gets it's power from the IG terminal on the key switch. If you got a short in the fuel sending unit wire it would take out the ignition system also. Toyota did not fuse the Ignition system to supposedly make it more reliable. I was going to remove the sending unit fuse and re-purpose it, but I think Toyota knew what they were doing. I think we should leave it alone.

This is the proposed new fuse panel layout...

All comments welcome!

 

[Indygbd]

Hey guys,
Long time between updates! Day job got REALLY busy this year! We are just starting to wind down. So back to harness building and working on the FJ25 harness!

After reading about the need to rearrange some of the fusing, I came up with a way to do it easily.

First thing I would do is make the third and fourth fuses on the fuse block, key switched fuses. This would be accomplished by first replacing the turn signal B+ wire on the key switch IG terminal with a 12ga wire and running that from the IG terminal on the key switch to the third center fuse of the fuse block. Next, making a jumper from the center fuse, to the fourth fuse below it, so that fuses three and four are now key switched. Then running a wire from fuse three to the turn signal flasher B+ terminal. That fuses the turn signals separately from the brake light(s) making it easier to trouble shoot.

Then Fuse #4 could be used for the horns and/or reverse lights, or if one preferred just use it for other accessories.

A way to gain yet one more fuse is to use the OEM FJ40 6 circuit fuse block which has three always hot fuses, and three key switched fuses. It will bolt right in to the FJ25.


Gas Tank Sending Unit Fuse Mystery Solved?
I may also have figured out why Toyota fused the gas tank sending unit. This seems to make no sense to anyone until you look at where the sending unit gets its power. It gets it's power from the IG terminal on the key switch. If you got a short in the fuel sending unit wire it would take out the ignition system also. Toyota did not fuse the Ignition system to supposedly make it more reliable. I was going to remove the sending unit fuse and re-purpose it, but I think Toyota knew what they were doing. I think we should leave it alone.

This is the proposed new fuse panel layout...

All comments welcome!

View attachment 1532335

What is the price to have a fj25 harness made? I am getting ready to start a fj25 restoration myself here in the next month or two.

 

[Coolerman]

I have yet to set pricing for these as I don't know how many I would be building or what "flavor" people want them in.
The options for "flavors" are:
Pure OEM using solid color wire, with colored heat shrink tubing for wire identification.
Pure OEM electrically but built using striped wire (like Red/Green) instead of colored heat shrink tubing on the terminal ends
Modified OEM 1 (see the post above about the fuse block changes) built with heat shrink tubing on the terminal ends
Modified OEM 2 (see above post about fuse block changes) built with striped wire
Custom: You tell me what you need and if it is reasonable, I will built it.

As a reference a 1964-1967 full harness set (main cowl, rear chassis, bib, wiper, headlight sub harnesses) runs about $800.00
Custom harnesses always cost the most of course.

 

[Indygbd]

I have yet to set pricing for these as I don't know how many I would be building or what "flavor" people want them in.
The options for "flavors" are:
Pure OEM using solid color wire, with colored heat shrink tubing for wire identification.
Pure OEM electrically but built using striped wire (like Red/Green) instead of colored heat shrink tubing on the terminal ends
Modified OEM 1 (see the post above about the fuse block changes) built with heat shrink tubing on the terminal ends
Modified OEM 2 (see above post about fuse block changes) built with striped wire
Custom: You tell me what you need and if it is reasonable, I will built it.

As a reference a 1964-1967 full harness set (main cowl, rear chassis, bib, wiper, headlight sub harnesses) runs about $800.00
Custom harnesses always cost the most of course.

Are those prices close to the same for different years? I have a 1972 that is down to the frame that I will building along with the FJ25 this winter. Do you take apart the original harness and rebuild it, or do you make a brand new hardness from scratch?

 

[Coolerman]

For harnesses before 9/1971, I build them new from scratch. For harnesses after 9/1971 I refurbish them. Harnesses after 9/1971 use connectors that are no longer available. Examples are the fuse block connectors. A refurbishment involves un-taping the harness completely, soda blasting the connectors to remove light dirt and corrosion, Repairing any damage to the harness and replacing any connectors that need it. (I try to leave the harness OEM as much as possible). The harness is then tested under full load and taped back up with non-adhesive harness tape. Price varies by year, with the later harnesses costing the most due to their increased complexity, but they start at $295.00 plus parts and return shipping. Regardless of year I build all rear chassis harnesses from scratch and for the later years that use connectors no longer available you must send me the old rear chassis harness so I can salvage the connectors.

I will NOT refurbish ANY main cowl harness that has been in a fire, or had a major meltdown in the main charge circuit.
I also will not refurbish one that has been painted over with paint or under coating, or is covered in a heavy coat of dirt and grease. It just takes way too long to clean those up.

 

[Coolerman]

Well, here it is! I had some time last weekend to devote to laying out the first "new" FJ25 harness! I elected to build one using striped wire and fuse block mods first. This is a shot of the harness after running all the wires and taping it into shape, but not terminated yet. I am tracking down the 4 sizes of metric spade and ring terminals needed. I want to do these using, as close as possible, OEM type terminals. If I have some more time this weekend I will start building the bib harness, the head lights sub harnesses and the gauge cluster harnesses.

On another note: Does anyone have an intact rear chassis harness they would like to loan me for documentation purposes? Probably asking for a pink unicorn, but thought I would ask...

 

[Indygbd]

Well, here it is! I had some time last weekend to devote to laying out the first "new" FJ25 harness! I elected to build one using striped wire and fuse block mods first. This is a shot of the harness after running all the wires and taping it into shape, but not terminated yet. I am tracking down the 4 sizes of metric spade and ring terminals needed. I want to do these using, as close as possible, OEM type terminals. If I have some more time this weekend I will start building the bib harness, the head lights sub harnesses and the gauge cluster harnesses.

On another note: Does anyone have an intact rear chassis harness they would like to loan me for documentation purposes? Probably asking for a pink unicorn, but thought I would ask...

View attachment 1539988

I have 3 FJ25's. I will check the rear harnesses out tomorrow for you.

 

[Coolerman]

Fantastic! I would promise to return it unmolested!

 

[nuclearlemon]

looking good. glad you still did this while on hiatus from harness building
now i need you to get back to production so i can get a harness for my 45

 

[Coolerman]

I AM back in production! I am already booked for the next 2 months so if you want a harness anytime soon you better send me a PM or an email with all the details.

This weekend I built all the sub-harnesses for the 1960 FJ25 harness except for the rear chassis harness. I am still trying to track down the correct ring and spade terminals so could not terminate anything yet.

 

[Indygbd]

Are you able to build a fj25 harness now?

 

[Coolerman]

Yes and no. Yes I can now build them as I have all the kinks worked out but have to stop harness building in the spring as my day job gets crazy... I usually start back up in the fall.

 

[67azcruizr]

Simple Trivia I haven’t heard mentioned yet.

While repairing a ‘59 Harness with a donor ‘59 Harness I unveiled an early “wire binding-pre wrapping” technique. I’ve concluded that perhaps all the harness’s were bound together with cotton string prior to receiving a final protective black wire wrap.
I’ve taken apart 2x ‘59 and 2x ‘60 Harness’s and all 4x were identical.

 

[1969FJ]

View attachment 1740890 View attachment 1740891 Simple Trivia I haven’t heard mentioned yet.

While repairing a ‘59 Harness with a donor ‘59 Harness I unveiled an early “wire binding-pre wrapping” technique. I’ve concluded that perhaps all the harness’s were bound together with cotton string prior to receiving a final protective black wire wrap.
I’ve taken apart 2x ‘59 and 2x ‘60 Harness’s and all 4x were identical.

You are correct. Japanese wiring used cloth to wrap before securing the bundle. Also, around that time ty-wraps were becoming the holder, in aviation. You can fill in the rest as any new item took time to get into the production world.


Wiring and Cabling: How To Lace Cable Harnesses

Cable tie - Wikipedia

 

[67azcruizr]

Does anyone have any legible wire Harness I.D. Tags?

I’d like to see what the font looks like, I don’t necessarily need Part#’s.

FJ25 only

 

[Coolerman]

Guys this year has been nuts with my day job. Normally this this time of year, I am slow. Not this year! I just returned from an installation trip in NOVEMBER!

However I do have an update. I was not able to locate the EXACT terminals Toyota used on these harnesses, but have gotten pretty close. I finished terminating the harness set I built last year and will tape it up today.

One other thing I am in need of.
I need the diameter of the hole in the head light bucket the head light sub-harness passes through. I am trying to locate a substitute grommet for that hole.

Mark aka Coolerman

 

[Coolerman]

I am also asking for anyone who may have the following part numbers for a 1960 FJ25:

Main cowl harness
Bib Harness
Generator Harness
Rear Chassis Harness
I know some of you guys have parts catalogs?

I just finished taping up all the above harnesses and would like to add the harness id tags to them.

Mark aka Coolerman