3F-E Conversion Thread (1 Viewer)

[lelandEOD]

I am looking to solicite some ideas/guidance from the group on a project I'm going to be tackling in the near future.

I've got a 3F-E sitting on my engine stand right now and it will soon be put in my '73 frame.

I've read every scrap of 3F-E conversion information I can find on the internet and while I don't think it's going to be easy I think there's enough information out there for me to sort it all out.

One major sticking point in my mind right now centers around the wiring of the 3F-E in the FJ40. As I see it, I have four basic choices:

1. Integrate/splice the necessary FJ62 ECU related harness components into the factory FJ40 harness:

-I am scared to death of trying to splice the necessary connections from the FJ62 engine management functions into the old FJ40 harness. I have not been able to find any information on the net that gets into a lot of detail (that I am able to understand) that describes how this is accomplished. This route would also likely create a headache with troubleshooting because I'd have to use both a FJ40 and FJ62 schematic and many wires would likely be different colors on either end.


2. Rip out everything and go with a custom made Painless harness:

-I don't want to use a generic/Painless harness kit because frankly, I think it would be harder for me to go this route as I won't have a factory diagram to rely upon to diagnose future malfunctions.

3. Buy the uber-expensive ($750) cruiserparts.net FJ40 3F-E wiring harness:

-I'm not jazzed about this because -well, for one- it costs a lot more than I've got invested in the entire drivetrain and two, I'm just not sure if it is truly plug and play. I've not been able to find any information from anyone that has successfully used their harness for a 3F-E conversion.

4. Replace the main FJ40 wiring harness with a trimmed down FJ62 main wiring harness:

-This is the direction I'm currently leaning. When I pulled my engine, I also grabbed the complete, unmolested main wiring harness from the donor truck. I think, with the limited amount of FJ40 switches and connectors under the dash, I should be able to use the complete FJ62 harness instead of the Fj40 harness. I'm thinking I can strip out everything from the FJ62 harness I don't need (auto transmission, AC, power windows, mirrors, cruise control, etc) to reduce the size of the loom. I'm hoping I can just trace the wires needed for the FJ40 turn signal stalk, hazard, ignition switch, headlights, etc. and re-wire the FJ62 leads to install into the FJ40 harness connectors. To me, this seems to be the most simple choice, barring the purchase of an $800 wiring harness.


Am I missing something obvious? Over thinking it? Making something overly complex?

I hope this thread will be a resource for those who are also looking to do this swap in their truck. Basically... if I can do it, anyone can do it.

Here is a list of all the 3F-E resources I've been able to find:




Pappy's Draft PDF (very helpful)

Rockdoc's 2F-E conversion

Elripster's FJ60 to 3F-E conversion

Dan Moeller's de-smoging guide (useful even though I will be keeping the smog parts)

Tools R Us build thread

73tlcv8's conversion pdf

Tucker74's excellent 3FE conversion thread

MMW68's 3FE build thread

 

[73tlcv8]

I was going to do the option 4 you describe but when I got the 62 dash harness apart, it was so way different, wire sizes, connectors, etc. It became obvious it was much easier to splice in the required parts to the FJ40 dash harness. There are only a few connections required to integrate the 3FE into the FJ40 harness (Oil pres gauge, Temp gauge, VSS, start, brake) compared to all the new connectors you will need to add or splice in (lights, hazard, wipers, ignition, heater) . You will need to figure out the switched and continuous power required by the ECU either way unless you change to the 62 steering column and ignition switch. I thought the difficult part was sorting out the pices of the 62 dash harness needed. I made some sketches when I figured it out. I have some time on Monday to dig them out and I can post them. I think the only benefit using the 62 dash harness is the better fuse panel, but figuring out all the other interfaces is a difficult task.

 

[lelandEOD]

I was going to do the option 4 you describe but when I got the 62 dash harness apart, it was so way different, wire sizes, connectors, etc. It became obvious it was much easier to splice in the required parts to the FJ40 dash harness. There are only a few connections required to integrate the 3FE into the FJ40 harness (Oil pres gauge, Temp gauge, VSS, start, brake) compared to all the new connectors you will need to add or splice in (lights, hazard, wipers, ignition, heater) . You will need to figure out the switched and continuous power required by the ECU either way unless you change to the 62 steering column and ignition switch. I thought the difficult part was sorting out the pices of the 62 dash harness needed. I made some sketches when I figured it out. I have some time on Monday to dig them out and I can post them. I think the only benefit using the 62 dash harness is the better fuse panel, but figuring out all the other interfaces is a difficult task.

That would be an absolutely HUGE help. Please post whatever information you are able to dig up on how you wired the ECU and related 62 engine management components into the FJ40 harness.

 

[tornadoalleycruiser]

Its not that hard. Sit down in an empty bay, lay the complete unmolested harness in front of you. I got mine running without the 45 harness attached. I bypassed the ammeter as the 62 alt has more juice. Cut out all the crap. It takes like three wires to fire it when ur done. I grafted the 45 harness to the 62 harness. Takes longer to unloom and unwrap than anything. Spend lots of time studying the wiring schematic. I would not use the whole 62 harness just what is necessary to fire the engine. Take apart your 40 harness and add a second fuse panel. The ignition switch for the 3fe has another circuit that took a bit of noodling.

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[lelandEOD]

Yup,

After getting feedback from here and on the yahoo 3F-E group, I decided that trying to run the FJ62 harness was overkill and a lot more work than necessary.

Now, I've got the FJ62 harness completely unwrapped and have been playing mad scientist with a pair of dikes. Snip snip here... snip snip there...

I've got it down to a surprising small amount of wires left!

Now, I've got the harness ECU connectors completely traced and tagged. One in particular really caused me a lot of headache. I have a Yellow/White wire coming from the ECU that I couldn't trace to save my life. Finally, I noticed (quite by accident) that in Pappy's thread he mentions the Check Engine Light is Yellow/Green or Yellow/White with a question mark by it. Sure enough... it looks like the factory schematic has an error on it. So, now i'm pretty sure I've got the Yellow/White wire pegged as the CEL lead.

Now for a few Questions:

1. Are you guys just running inline fuses to protect the ECU leads or did you find it necessary to wire a stand-alone fuse panel?

2. Is it ok to just cap off the unused ECU leads (i.e. Tachometer, 4 wheel drive indicator light, A/C Amplifier, etc.)?

3. How did you bypass the neutral start switch? I didn't get the switch with my engine/harness, just the wires leading to it.

4. Can someone explain to me how they wired the FJ40 ignition switch for the extra FJ62 circuits?

5. What's the deal with the FJ62 Vehicle Speed Sensor? I've got the Green/Black lead from the ECU connector to the VSS identified but am not sure what to do with it? Is the VSS even necessary with a manual transmission? I thought it was used to help the transmission computer decide what gear to be in?

6. I would like to use the unaltered FJ62 alternator connections. Will this cause problems with the FJ40 amp meter?

7. Is the Engine Cooling Fan, relay and controller necessary? I haven't seen any mention of it in the threads I've read. Can this just be deleted?

 

[Living in the Past]

5. What's the deal with the FJ62 Vehicle Speed Sensor? I've got the Green/Black lead from the ECU connector to the VSS identified but am not sure what to do with it? Is the VSS even necessary with a manual transmission? I thought it was used to help the transmission computer decide what gear to be in?

6. I would like to use the unaltered FJ62 alternator connections. Will this cause problems with the FJ40 amp meter?

Not sure what the VSS is for but the A440F is not a computer controlled transmission.

I think #6 depends on which amp meter your running. I believe on the early FJ40 it would fry the meter. I believe that changed in the late seventies.

I am following your thread since I finally picked up a 3FE to install in my 65 FJ45LP-B. Wiring is my biggest question. I believe I have a 80 FJ40 wiring harness I will mix with the FJ62 harness. It should work better the 65 harness. What senors do you plan on using for oil pressure and water temperature? Probably go with a late cluster so I can hopefully get away using 40 series gauges.

 

[tornadoalleycruiser]

Im using the ac later. Tach i capped. I documented the switch wiring in my thread. I put in a voltmeter to bypass the ampmeter. Wire nss to bypass the switch. Solder the leads together.

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[lelandEOD]

What senors do you plan on using for oil pressure and water temperature? Probably go with a late cluster so I can hopefully get away using 40 series gauges.

I'm planning on modifying my gauge cluster to more modern Autometer gauges from Amateur. This should knock out a couple problems.

 

[lelandEOD]

Im using the ac later. Tach i capped. I documented the switch wiring in my thread. I put in a voltmeter to bypass the ampmeter. Wire nss to bypass the switch. Solder the leads together.

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Oh, man! Your thread is going to be very useful to me. I have read it before but must have missed the details on the ignition switch modifications...

Thanks!


Also, I didn't see it posted specifically... did you get the FJ62 VSS to drop in to the FJ40 cluster? I assume the whole plastic assembly wouldn't fit so you had to disassemble it and get all speedo-ninja on it or something? I don't have several old speedo's laying around to play with so I'd rather not destroy one trying to make something fit. Any advice?

Thanks again guys!

 

[mmw68]

I was under the impresion that Amateur has shut down his store?

Good luck with the 3FE install!!!!

I'm planning on modifying my gauge cluster to more modern Autometer gauges from Amateur. This should knock out a couple problems.

 

[lelandEOD]

He has shut down the web store but his fiance is running the business as (I suppose) time allows. You just need to email them directly. I just ordered a kit tonight and Kelly said it should ship next week.

 

[73tlcv8]

Sorry, I was covered up on Monday, I will get the wiring diagrams tomorrow.
1) I used in line spade type fuses for the ecu. These need to have good connections.
2) Yes, but recommend you leave them dangle out of the harness a little in case you want to use them in the future.
3) Connect nss leads together
4) Wire a relay coil to the existing engine fuse so it picks up and closes the contact when the ignition switch is in run position. This is your second switched power contact you can use for the ECU.
5) The VSS wire is just connected to the VSS reed switch on the back of the fj40 speedo. Other side of reed switch should be grounded already.
6) I converted an oil pressure gauge to operate as a voltmeter. Your new autometer gauges can do the same.
7) I'm not running the cooling fan, no issues last summer.

 

[tornadoalleycruiser]

The ignition switch wiring im running might not be correct. I pulled my oil pan off to swap then got distracted by my ADD need to get the bed togerher and havent gotten back to the front of the truck. So relay is the other solution to run the other ignition circuit. I havent fired it since i changed that. Figured exhaust was needed and to do that i needed a lot more stuff in the way like my pto and bed.

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[tornadoalleycruiser]

Vss is in certain 40 clusters. Not positive it is needed yet but wired it anyway. Different clusters run different pulses as well.

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[PabloCruise]

Looks like you have done your reading thus far, good job.
I'll be interested in reading how you decide to proceed.

 

[lelandEOD]

Thanks for the replies and words of encouragement, guys.

The most daunting aspect of this, by far, has been the wiring. I get sick to my stomach when I think of cutting into two perfectly good wiring harnesses.

I'm firmly committed to grafting the 40 harness to the 62 harness (or vice versa) at this point. Here's a photo of the state of affairs last night:

I'm committed now.

The only things I'm keeping from the 62 harness are the ECU leads (including peripherals such as the fuel pump lead, neutral start switch, etc.) and the alternator charging leads to the fusible link. This should (I think) ensure that the harness can handle the increased loads from the 62 alternator. Right now, I'm trying to decide if I want to add a second fuse panel (like a 6 fuse panel) that I can use to run the ECU stuff or if I should just dump the factory glass tube panel in favor of a new style aftermarket panel. Or, I could even try and find a way to use the 62 fuse panel. ... haven't decided if I want to open that can of worms.

More to come!

 

[tornadoalleycruiser]

This help? Way easier to add a fuse panel. One is switched hot one is hot. I can add stuff later as well. Here is my leftover box of 62 wires.

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[tornadoalleycruiser]

Ur on the right track. Its pretty cool to hit the key on it in the end. Time and patience. Took me longer to order fittings to goto metric and an to ulilize stock fuel filter than to do most of the wiring.

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[73tlcv8]

3fe schematic

hope this helps

 

[PabloCruise]

hope this helps

This thread is turning into a very good resource for the electrical work required to do the 3FE swap.