4.0 swap Simplify harness

[kieth tyrrell]

I have a 84 bronco 2 that I swapped a 93 ranger 4.0 into, about 10 years ago. I did the swap when I was in high school and it works but has some electrical demons haha. Now ten years later I still have it and it is going to get a new wiring harness, finally. I just got a 93 explorer with bad head gasket for a harness donation vehicul. I think this harness is going to be a bit nicer under the hood layout looks much similar to the bronco2...

my question is I wanna eliminate some plugs on the harness. Don’t want AC. Don’t want ABS. Don’t want cruse control. Might be forgetting some others I was gonna not use....
Can I cut this stuff out of my harness without any isuss or dose some of this stuff need to be plugged in to keep other components from wigging out?

 

[410Fortune]

YES
remove it all
I like to strip the harness down to just the essentials and then route it better then the factory under hood routing.

1984 BII does not need many wires on the truck side of things, maybe 16 wires left when you are done for the fuel pump, dash, etc

1993 power distribution box is the BEST for this
You will end up with like 2 fuses and 2-3 relays
EEC relay, WOT AC relay and FUEL relay
fuel pump fuse, EEC fuse and a dash fuse box power feed fuse

This leaves the rest of the fuse and relay locations open for you to add accessories
My 88 BII still uses the 93 power distribution box. I put it on a plug so I can remove it and put it on the bench. I like them so much I added a 93 explorer power dist box to my wifes FJ cruiser to handle all of her accessories also

I did similar to you, WAAAAAAAAY back i converted my 88 BII from 2.9/ 5 speed to a 4.0 and 5 speed I had help with the wiring harness and it RAN, but that was about it. The next two years I re did the wiring and sorted it all out....that was my first wiring/conversion since then I have done many 4.0 and 5.0 conversions
You can strip the engine/trans harness down to the essentials
AND
you can simplify other circuits to your liking.
Just start tracing out the wires you need, an un pin the ones you don''t.

Here is an example of a completely stripped harness, this was 97 explorer to 1949 Ford F1 I removed everything not needed for the truck bumper to bumper it is amazing how little is needed to make these run and talk to the truck

 

[kieth tyrrell]

You just blew my mind. I figured this forum wouldn’t even help but I figured I’d try. So another thing is I swapped the whole dash from the 93 ranger back when I did all that and now I wish I woulda kept the stock dash. Should I look around for a first gen dash and harness?

 

[410Fortune]

93 dash is cool
I have put a 92 dash into a 84 ranger
The 89-94 dash and steering column take up ALOT of room in the BII cab
I prefer my 88 dash
so that is totally up to you


I have kept the 88 dash in my BII
My BII went from 2.9 and 5 speed to 4.0/5 speed to 4.0 and auto to finally 5.0 and auto
I still have the 88 dash, 93 power distribution and 97 5.0 drivetrain wiring
I am still using the 1988 through firewall wiring (one rubber plug)

The 93 dash you installed has ALOT of un needed wiring too
Did you install the big white wiring plug in the firewall with that 93 dash?
I have the wiring diagram for that plug somewhere...shows what wires I removed and what we kept

 

[kieth tyrrell]

Yes I used that big white round plug on the drivers side fire wall.
I really want to get another first gen dash and steering column. I just felt like I had no other option back then and thought I better put the dash from the donor ranger.

Now that I am going to tackle this swap for a second time I think I could figure out somehow the first gen dash wires. And simplify the engine compartment harness. To make it all work.
You know you are really making me feel much more comfortable with cutting this harness open I appreciate your time!

 

[410Fortune]

no problem
passion of mine is converting these RBV (ranger based vehicles)
4.0 in a BII is like how Ford should have built them
the 2.8 and 2.9 cologne v6 belong in sedans
the bored and stroked 2.9 we know and love,AKA the 90-2000 pushrod 4.0 ohv is one wicked cool engine
In a BII they are perfectly suited for daily and trail duties, even towing

 

[kieth tyrrell]

Where did you get the best wiring diagram or scamatics, Or did you just trace each wire by wire? What’s the best methods and place to start simplifying the harness. You start at the fuse block?

 

[410Fortune]

I have all the wiring books from 89-94 and then some other various books and schematics as well
I will share with you some 4.0 wiring info that will be very helpful, I might have to get the papers and scan them in
I have piles of notes from each conversion I have done over the years.....

The power dist box gets many wires removed, as does the big white plug, and just a few from the engine harness
Most of the wires you take out will be from the dash, power, under hood ABS type stuff.
I routed ALL the wires on my BII along the back of the engine, nothing through the intake or around the front core support...much cleaner this way

 

[kieth tyrrell]

I will take all the information you are willing to give me. Pictures would help me a lot too. I am worried my harness is going to become a rats nest if I don’t have some scamatics or something to get me started taking lum off

. I have the explorer under hood harness out all except the ecm plug that is going trough the fire wall passengers side . Just have to work on fighting that big ac condenser box.

 

[bats]

Subbing for some of 410's modified wiring diagrams.

When I did the swap 4.0 swap 5 ish? years ago I literally cut and pasted everything from the donor 94 Explorer including the dash. In retrospect I wish I had kept the original Bronco dash but I digress.

Over the years I've been slimming down the wiring harness. Here's what I remember off the top of my head:

Really the only wiring that needs to run to the rear are the brakelights and tail lights. Start at the tailights and work your way back. Wrap those wires into a loom of their own.

The rear passenger doors had a lot of wiring for power windows/locks and speakers. I forget what the plugged into but I tagged one wire for keyed power and dead headed it for future use.

The engine harness really isn't that bad, even with all the EGR crap. ABS and AC wiring could be removed or just tied up somewhere. I just unplugged the ABS module in the engine compartment and it doesn't throw any ABS codes.

It all comes down to how particular you want to be.

 

[Josh P]

I like the nostalgic look of the dash in the 1st gen, ford used that style for many years.

 

[kieth tyrrell]

I wish I would have never got rid of my stock dash. I hope I can find another one. I will keep my eye out for one and hopefully find one befor I get much further into this project.

Bats thanks for all your added info and knowledge. I like the idea of starting in the back of the rig where the tail lights are. Just like you when I did this swap 10+ years ago I swaped 4.0 and dash and every wire on the whole truck. took everything from a 93 ranger That was parked next to my freshly striped bronco 2 and I started moving everththing over. I have a lot of messy wires and the ecu just bouncing around under the hood because the ranger had it in the firewall on the drivers side.

I think I will have better luck with this the second time. I like this forum everyone is really nice and helpful. I usd to use the ranger station along time ago and just can’t seem to figure out there website anymore.

Still gotta get some good scamatic and wire diagram for this 93 harness.

 

[410Fortune]

Ill get some schematics for you and post my own notes from a very similar conversion (84 ranger to 92 4.0)

I love my 88 dash...so slender and simple....big pocket on pass side for stuff, big round tach and speedo....of course mine is far from stock these days underneath

 

[Josh P]

car-part.com has dash panels listed, find a yard that will ship to you.

 

[410Fortune]

shoot I can get a Gen I dash no problem these trucks are still in the junk yards. You may also check your local craigslist and get one from a private party. I expect $100=150 could get a whole dash /steering column
the hard part is getting the OEM dashpad with no cracks

1983-88 bronco II and Ranger had the dash you need. Dependiong on the color of your interior you can always vinyl paint it to match your truck. My current dash pad was red when I got it, I prepped and painted it the mocha color I need and it has held up perfectly for 10+ years now

 

[kieth tyrrell]

Yeah I painted the 93 dash that mocha color to match my interior.

I will be able to find a dash but yeah I know the dash pads are the parts that get all brittle and crack. The local junk yard here has 7 rangers in that first gen era I will probably be able to get a dash from but never get bronco2s. I always try to look for good seats for my bronco2.

 

[bats]

First gen explorer seats fit really good. I'm 85% sure the holes in the seat for the brackets line up but I can't remember exactly how I did that. Second gen Explorer seats work well too but you might have to drill a hole or two.

 

[410Fortune]

Gen II seats the front holes will not line up you can make some simple brackets to go from the stock hole to the new seat or you can chop cut weld the gen II seat feet and put them where they need to go.
I have 2001 Eddie bauer power leather buckets in my BII, at first I had the simple brackets to re locate the front bolts and now I have cut the set bases and welded them into the correct spot.
I just did this last week and I am getting ready to post pictures

I will get the wiring info posted for you this week
This whole week is work in the shop week for me so I will have much time for truck stuff, helping w wiring

 

[kieth tyrrell]

Got the harness out and it’s got way to much goin on what a mess of wires.

 

[410Fortune]

exactly
start at the power box and the non needed plugs like ABS and start removing wires one at a time.
I like to clean the whole harness before I begin to cut the conduit and tape off