FJ40 2FE Cowl Harness Instructions (1 Viewer)

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May 3, 2013
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335
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Upstate South Carolina
Finally having time to get to this project I had put on hold for a few years. I had the entire cruiser stripped down and blasted years ago about the same time I built my mustard 73'. With this cruiser I wasn't sure what I was going to do an how far I wanted to go as far as original/stock etc. I finally decided with some help from the wife as she picked the Freeborn Red color and with the fact I had enough good restorable stock parts to go back as original as possible. Then a slight wrench in my "stock" plan as I started down the rabbit hole after acquiring a 3FE head and harness. I am currently getting ready to dive into the wiring harness after spending hours melting my brain reading everyone else's threads and deciding which route to go.

I have decided to graft the 89' FJ62 harness into my FJ40 harness after cutting out everything I don't need which I think I have figured out from threads by @lelandEOD , @tornadoalleycruiser , @73tlcv8 and a few others. I wanted to put together a somewhat step by step of how I am approaching this process to serve as instructions for anyone who may decide to tackle a similar project project in the future. I know there is more than enough information on previous threads if you combine and sort through information but I have not seen anyone put together a simple to follow process for the people who may not understand a lot of the jargon related to electrical components and how the function and communicate with each other etc. I may be wrong and maybe there is something like this out there but I have not found it yet so if there is please let me know. I am also hoping others who have traversed this task will input their suggestions based on their experiences doing this so we can build on these instructions over time.

Here we go.....

Disassembly:

1. Lay out both the FJ62 and FJ40 harness's on the floor or working surface
2. Cut loom and electrical tape off the harness's carefully not to rearrange the layout of plug/wiring locations
3. Take pictures of the harness for reference just in case.
4. Download/print schematics for the FJ62 harness attached to this thread I copied from @73tlcv8
5. Label each wire on the main ECU plug from the cowl harness using the schematic Fig. 2 and follow each wire on the schematic to see where it goes this really helped with the overwhelming effect you get at first looking at the mess of wires. It starts to build an understanding of the process and identifying what wires you will need and what you wont.
6. Familiarize yourself with this list of needed components needed from Pappy's Draft as this is the source of my step by step which is basically a continuation of his cowl harness section of the write up he did. http://bushrat.hdcruisers.org/3FEconversion.pdf
The cowl harness has EFI connectors for: • ECU (1) • Engine harness • Air flow meter • Ignitor • Main relay • Circuit open relay • Fuel regulator VSV(B-L + R) Plus, it has wires for: • EFI Fuse (R-Y) • Ignition Fuse (B-L) • Speed sensor (G-B) • Start switch (B-W) (splice to B-R) • 4WD switch (Y-B) • Brake light switch (G-W) • Ground (BR) • A\C (B-W) • Check engine light (Y-G, Y-W?)
This is also the document that i studied when I built my engine to help clarify what components I would decide to deleted and what I would use eventually.
(See pictures for each connector or wire shown to identify)
7. Now that you are familiar with the connectors and wires you need and their locations you can start the process of cutting out the stuff you don't need. I will be starting from the alternator and working my way back from there.
8. Clip the Yedl/red wire from the EGR VSV where it attaches to the AI & FPU VSV's so you can remove the AI & FPU dual use connector from the rest of the alternator wires. Separate the connector all the way back to the main ECU plug.
9. Working your way back to the main fuse block cut the large Red/Yel wire from the back of the 15 amp EFI fuse location and separate it from the harness.
10. Next fuse over is the 7.5 Amp Ignition fuse. Cut the smaller Black/Blue wire from the back and separate it from the harness as well.
11. Moving back to the keyed ignition switch harness connector I cut the Black/blue wire that goes to the ignitor from the back of the connector where it was factory crimped to the fused ignition feed and separated it out of the harness. Also cut and separate the smaller Black wire at the back of the tachometer connector that also goes to the ignitor. This wire gets capped off but I am keeping it long for now in case I decide to hook up a tachometer later.
12. From here I moved to the main ECU plug and separated the previously labeled wires for the Speed Sensor (VSS) Green/Black, Ignition start switch Black/White, 4WD indicator light switch Yellow/Black, Stop/Brake light switch Green/white, CEL (check engine light) Yellow/white. These wires were already cut near the ECU plug when I received it so I will extend them as needed to reach the components. You can trace them out to where they go and cut them so you have longer leads.
13. Moving past the ECU plug toward the battery I cut and separate the White/black wire and the Brown wire at the main ground lug. These two wires go back toward the fuse block and tachometer. Don not cut the other three Brown wires that go toward the battery side they go to the Main EFI relay, Circuit opening relay and the air meter connector.
14. Next in line is the Circuit opening relay. Separate it from the main harness. All of the wires from the relay should be connected except the Red/Green which is to the fuel pump.
15. Next is the main EFI relay to be separated. All the wires from this relay should be connected.
16. Separate small Black/white A/C amp wire.
17. Last is separate the ignitor and air meter connectors from the last section of harness that goes to the battery.
18. Everything needed should now be separated from the original harness and everything else can be tossed in a box.

Assembly:

1. Lay out the FJ62 harness over the FJ40 harness aligning the desired locations of the FJ62 components like where you want the ECU to mount. I laid my harness starting with the ECU plug being located in the glove box where mine will be mounted in the FJ40. The FJ40 harness has the connector for the factory plug in work light outlet in the glovebox that worked good to identify a starting point.
2. The only component I ran over the harness toward the driver side of the harness and out the firewall toward the front left was the one 4 pin connector that will control the FPU (Fuel pressure regulator VSV.)
3. I ran the main EFI relay, circuit opening relay, air meter connector, Igniter and A/C Amp connector out the passenger side firewall and attached attached them just past the blower motor connector on the original FJ40 harness. I will finish securing the components and tidy up the wires when I install the harness.
4. I ran the main Red/Yellow EFI 15 Amp power wire out the passenger side as well and will be installing an aftermarket 6 way fuse block near the battery.
5. The ECU Black/Blue power wire, the Black/Blue igniter wire and the Black/blue wire from the injectors coming from the connector at the cowl to engine harness will all be ran out the passenger side as well and be connected to the new ignition relay shown in Fig 1. Each of the 3 wires I will run to the new fuse block and put a fuse in line between the relay and each component. 7.5 Amp for the ECU, 7.5 Amp for the igniter wire and 10 Amp for the injector wire. I will also run a feed wire from the Black/Yellow off the ignition switch and run it to the new fuse block and install a 25 amp fuse to power the new ignition relay.
6. Moving to the ECU connector the next wires to hook up will be the Black/White Ignition start wire which will be soldered to the Black/Red ECU wire that sends signal to the circuit opening relay, cold start injector, starter motor as well as it is bypassing the neutral start switch. These will be soldered to the Black/White wire coming from the FJ40 ignition switch and will get signal when the switch is turned to the start position.
7. Next wire at the ECU plug is the CEL (check engine light) and I will be wiring this to an indicator light on the dash just haven't figured out where I want to put it yet.
8. Next at the ECU plug is the Green/White stop light signal which will get soldered to piggyback off the Green/White wire at the FJ40 brake pedal switch.
9. Last wire I am using from the ECU plug is the Green/black speed sensor (VSS) wire which will be connected to the back of the FJ40 instrument cluster which I have a 3rd/4th gen barrel connector style so I will be soldering the VSS wire to the white VSS jumper wire on the cluster. (See pic.)

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Joined
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Messages
335
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Removing the tachometer, main fuse block, relay block, and EGR VSV connector. Cut the small Black/blue wire from the fuse block for the 7.5 amp ECU power feed and keep.

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Joined
May 3, 2013
Messages
335
Location
Upstate South Carolina
Keep the FPU/AI VSV's connector. Remove the manifold temp sensor connector and alternator wiring. Cut the Red/yellow from the fuse block for the main EFI relay power feed and keep. Black/blue factory crimp below the ignition switch connector where I cut the wires for the igniter and injectors feed and kept.

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Joined
May 3, 2013
Messages
335
Location
Upstate South Carolina
A/C Amp wire I am keeping. EFI Harness after removing unnecessary wiring. Left overs. EFI harness where I started to lay onto the FJ40 harness at the glovebox. Cowl harness to engine harness connector.

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Joined
May 3, 2013
Messages
335
Location
Upstate South Carolina
Cowl harness to engine harness connector. Back of the instrument cluster I am attaching the speed sensor (VSS) from the ECU to the white wire. Cowl harness to engine harness connector diagram. My version of Fig. 1 ignition relay and fuse block I am doing.

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KC Mo
Joined
May 3, 2013
Messages
335
Location
Upstate South Carolina
Excellent job! As I read thru that I had flashbacks. Feel free to grab anything off my thread that might b helpful. Which alternator are you going to run? If fj62 don't forget I have the alt diagram in this post. Tornado takes the top off 1964 SWB FJ-45 - https://forum.ih8mud.com/threads/tornado-takes-the-top-off-1964-swb-fj-45.522904/page-17#post-11572742
Really only need to pay attention to the sensing wire to turn the alternator on.
Thanks for the input! I haven’t decided about the alternator as this was one of my questions I needed to research. I noticed in yours and others threads using a 62 or alternative. Is the stock 40 alternator not enough to run the EFI system?
 

Curtice

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Joined
Jun 15, 2010
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1,041
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Issaquah, WA
Good stuff. What are you doing about the yellow-black 4wd signal wire? Just cap this? I can’t figure where to take it. My 40 has no 4wd indicator or tcase wiring that I’m aware of.
 

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