• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

1990 Bronco II, 4.0 engine swap.....Help


pjksr1955

New Member
Joined
Mar 5, 2009
Messages
2
Reaction score
0
Points
0
Vehicle Year
1990
Make / Model
bronco 11
Transmission
Manual
I have a 1990 Bronco II with a manual transmission. I purchased a 1994 4.0 engine with wiring harnesses and computer. Engine and transmission is in truck. I need to know what to do electrical. Please HELP.....thanks
 


adsm08

Senior Master Grease Monkey
Supporting Member
Article Contributor
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
34,623
Reaction score
3,613
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
plug it in.

The 90 is pretty much a direct plug'n'play for the 4.0, assuming you came up from a 2.9L.
 

trail B2

New Member
Joined
Jan 17, 2009
Messages
1,289
Reaction score
8
Points
0
Location
North Eastern Ca.
Vehicle Year
1986
Make / Model
ford
Engine Size
4.0
Transmission
Manual
I took one out of a 93 Ranger and I wound up building a container for the ECU on the drivers side out of a metal fuel can.Start at the dash which should plug in and work your way around till you get to the heater controls.Get most of it all together like the dash and injector plugs then work out like windshield squirter at the end decide if its easier to move wiring or the tank.I really think that not cutting main wires like ecu wires is the best way for long term reliability.
 

Xandor

New Member
Supporting Member
TRS Banner 2010-2011
Joined
Oct 27, 2009
Messages
368
Reaction score
3
Points
0
Location
Bloomfield IN
Vehicle Year
88, 89, 89
Make / Model
Ford
Engine Size
2.9 2.9 2.3
Transmission
Automatic
plug it in.

The 90 is pretty much a direct plug'n'play for the 4.0, assuming you came up from a 2.9L.
This I didnt know.
 

BlackBII

Ranger Custom
Article Contributor
OTOTM Winner
TRS Banner 2010-2011
Truck of Month
Joined
Aug 14, 2007
Messages
7,895
Reaction score
982
Points
113
Location
UT
Vehicle Year
1989
Make / Model
Ford
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
4WD
Total Lift
5
Tire Size
33
The ONLY 4.0 swap that will be 'plug and play' will be a '90 BII 5 speed to a '90 Ranger 5 speed, both will manual windows. Ask me how I know. :D

Even then, I had issues with Wipers, Taillights, reverse lights, Radio.....

Nothing will be 100% plug and play. But a '90 BII to a 90-92 Ranger or a 91-93 Explorer will be easiest of all the swaps. There will always be wiring differences that will need to be sorted out. Get a wiring diagram for both vehicles and start swpping pins on the cannon plug on the drivers side firewall, there will be differences.

You swap the entire engine bay, from the cannon plug all the way around to the passenger side, through the firewall and into the computer. Swap it all over.
 

YOUNG GUNS15

New Member
Joined
Feb 13, 2010
Messages
4
Reaction score
0
Points
0
Vehicle Year
1986
Make / Model
Ford
Transmission
Manual
well that little speach right there killed my swap for me.... plus working on these little fords is driving me crazy.... id rather work on my dodge cummins
 

justcoffee

New Member
Joined
Nov 19, 2010
Messages
2
Reaction score
1
Points
0
Vehicle Year
1990
Make / Model
Ford
Transmission
Manual
I did the Bronco 11 engine swap to a 4.0, 5 years ago...

The Swap was not that hard. If you still need my input, e-mail me and I can still walk you through it. It works fine. Justcoffee
 

justcoffee

New Member
Joined
Nov 19, 2010
Messages
2
Reaction score
1
Points
0
Vehicle Year
1990
Make / Model
Ford
Transmission
Manual
Go For It

I have a 1990 Bronco II with a manual transmission. I purchased a 1994 4.0 engine with wiring harnesses and computer. Engine and transmission is in truck. I need to know what to do electrical. Please HELP.....thanks
I did this, and was a no brainer...Justcoffee...
 

hoofnit

New Member
Joined
Oct 13, 2008
Messages
6
Reaction score
0
Points
0
Vehicle Year
1989
Make / Model
Ford
Engine Size
2.9l
Transmission
Manual
doing a 4.0 swap into an 89 BII swap now...what did you do at the heater plug ?
Mark
 

BlackBII

Ranger Custom
Article Contributor
OTOTM Winner
TRS Banner 2010-2011
Truck of Month
Joined
Aug 14, 2007
Messages
7,895
Reaction score
982
Points
113
Location
UT
Vehicle Year
1989
Make / Model
Ford
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
4WD
Total Lift
5
Tire Size
33
doing a 4.0 swap into an 89 BII swap now...what did you do at the heater plug ?
Mark
Heater plug?

Care to explain the issue you are having a little further?
 

hoofnit

New Member
Joined
Oct 13, 2008
Messages
6
Reaction score
0
Points
0
Vehicle Year
1989
Make / Model
Ford
Engine Size
2.9l
Transmission
Manual
Seems that the heater motor draws power from the relay box on the new harness, instead of the fuse box on the original Bronco II harness...in the tech forum write up they talk about having to splice 4 wires for the heater to work but there is no detail about this...just wondering what works here...I have both heater harnesses they are very similar except for the incoming power wire on the newer one. I have an 89 BII and am using a 92 ranger harness...& 4.0 motor and m5od.
 

greasemonkey6886

New Member
U.S. Military - Veteran
Joined
May 13, 2010
Messages
278
Reaction score
0
Points
0
Location
Sulphur Springs, Tx.
Vehicle Year
88,89,07
Make / Model
Ford
Transmission
Manual
Not completely shure of your 89 wiring just yet even though I own one. I just completed a 4.0 swap on my 88 and just used the factory heater harness since it wasnt removed during the swap anyhow. The 88 as you stated on your 89 draws its power from the fuse box under the dash and all the wiring for it is inside under the dash except for the small amount of it that plugs into the heater fan and such. Since I retained all of the "dash" wiring all I had to do was provide power to the fuse box under the dash by hooking it to the new power distribution box that came from my donor explorer harness. This winds up giving you an extra form of protection in the way of a second fuse in the distribution box. However, I know for a fact that your 89 had a distibution box from the factory so I suggest that if using the donor distribution box just connect up the dash harness power to the new distribution box in the same place as the donor was hooked up. All should work then.
 

hoofnit

New Member
Joined
Oct 13, 2008
Messages
6
Reaction score
0
Points
0
Vehicle Year
1989
Make / Model
Ford
Engine Size
2.9l
Transmission
Manual
That's what I'm going to try first, just plug in the original stuff and see if it works...If it doesn't it appears the difference is only that the power wire that plugs into the resistor plug on the newer harness comes from the distribution box instead of the fuse box under the dash.
 

RacinNdrummin

Member
TRS Banner 2010-2011
Joined
Dec 21, 2008
Messages
629
Reaction score
7
Points
18
Location
Auburn, Wa
Vehicle Year
2005
Make / Model
Ford
Engine Size
3.0
Transmission
Manual
The ONLY 4.0 swap that will be 'plug and play' will be a '90 BII 5 speed to a '90 Ranger 5 speed, both will manual windows. Ask me how I know. :D

Even then, I had issues with Wipers, Taillights, reverse lights, Radio.....

Nothing will be 100% plug and play. But a '90 BII to a 90-92 Ranger or a 91-93 Explorer will be easiest of all the swaps. There will always be wiring differences that will need to be sorted out. Get a wiring diagram for both vehicles and start swpping pins on the cannon plug on the drivers side firewall, there will be differences.

You swap the entire engine bay, from the cannon plug all the way around to the passenger side, through the firewall and into the computer. Swap it all over.
I disagree, if you get a 90 ranger harness, its completely plug and play. Other than making it fit to my SOHC, the harness itself is untouched and everything works perfect for me...
 

Moses1776

New Member
Joined
Sep 7, 2022
Messages
8
Reaction score
3
Points
3
Location
Anderson, SC
Vehicle Year
1990,1994
Make / Model
Bronco2, Ranger
Transmission
Manual
I did the Bronco 11 engine swap to a 4.0, 5 years ago...

The Swap was not that hard. If you still need my input, e-mail me and I can still walk you through it. It works fine. Justcoffee
lol whats that email. 1990 Bronco II 2.9L to 4.0 swap in progress.
 

Sponsored Ad


Sponsored Ad

Staff online

Members online

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Kirby N.
March Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top