4.0 swap wiring insanity


Shran

Junk Collector
Supporting Member
Article Contributor
V8 Engine Swap
Solid Axle Swap
Joined
Mar 4, 2008
Messages
4,250
Reaction score
89
Points
48
Location
Rapid City SD
The recipient is a 1989 Ranger that was a 2.9/5 speed/4x4 truck. No power options except cruise. No AC.

The donor was a 1994 Explorer with a 4.0, auto, electric 4x4, and almost all power options. (PW, PL, power seats, and premium radio amp. No DRL or the Limited options.)

The Ranger received a M5OD and 1350 manual t-case during the swap.

The Ranger was stripped of all wiring except the tail lights, fuel pump and dome light. I used the Explorer headlight harness, dash, and dash harness. This was done so that I can have AC and not have to repin the Ranger dash cannon plug. I spliced the appropriate wires for tail lights and fuel pump and now I have a truck that runs...

... but the problem is that the heater controls do not work. In fact, the heater blower knob turns the dash lights on and controls their brightness. And when the "heater" is on, the indicator lights for the turn signals are both on and get dimmer or brighter but the blinkers function normally.

I'm not sure how to troubleshoot this. I have disconnected all of my spliced in plugs and gone back to how it was in the Explorer from the factory and nothing changes. I have gone so far as to pull every unrelated fuse, relay, and harness plug and the only ones that make a difference are on the heater harness - if I unplug the blower motor, resistor, or big pink/white wire, the issue disappears, but obviously the blower motor still doesn't work and the dash lights also don't work.

My thought here is that the blower motor relay is tied into the Daytime Running Lamp module (or in my case, the DRL bypass plug since it doesn't have DRL) through the purple/orange wire and thus the turn signals which is feeding back through the headlight switch plug and the dash lights.

Thoughts? This was all functional when I removed it from the Explorer... it is just so odd that is doing this weird shit now that it's in another cab.

FWIW I have tried a 1993 Explorer dash harness and have unplugged and replugged everything on the harness a dozen times or more and checked/recheck grounds with virtually no change.
 


Rock Auto 5% Discount Code: 248EE46702D889 Expires: October 1, 2019

adsm08

Well-known member
Supporting Member
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
31,638
Reaction score
1,018
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
What did you do?
 

BlackBII

Ranger Custom
Article Contributor
OTOTM Winner
TRS Banner 2010-2011
Joined
Aug 14, 2007
Messages
7,364
Reaction score
117
Points
63
Location
UT
Vehicle Year
1989
Make / Model
Ford
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
4WD
Total Lift
5
Tire Size
33
Yeah man you have to have a wire or two crossed somewhere.

I just did a similar swap; put a '92 Explorer 4.0, dash and harness into my '89 Ranger and had zero issues.

Do you have the wiring diagrams for the explorer? If not I can post some.
 
Last edited:

adsm08

Well-known member
Supporting Member
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
31,638
Reaction score
1,018
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
It shouldn't do that.

I do vaguely remember another report of a similar swap doing exactly this same thing. Unfortunately I have no idea how, or even if, it was ever fixed.
 

Shran

Junk Collector
Supporting Member
Article Contributor
V8 Engine Swap
Solid Axle Swap
Joined
Mar 4, 2008
Messages
4,250
Reaction score
89
Points
48
Location
Rapid City SD
Ha. Yeah, definitely should not do what it's doing. Thanks for the offer of the wiring diagrams - I have a ton of them - just not sure where to even look as I'm just not seeing how the heater controls are tied into the dash lights and turn signals except by way of the DRL module which I don't have.

Wires crossed is entirely possible, maybe rubbed through somewhere? It crossed my mind that maybe the dash lights run through the electronic 4x4 control module but I plugged all that back in and still no change.

Just is weird that I can unplug all of my splices and the problem still exists - almost like there's something missing from the harness that the dash lights/heater controls would have been routed through.

FWIW I also do not have any of the ABS stuff present - the ABS pump, wheel sensors, relays and fuses in the power distribution box were removed and discarded.

I'm almost at the point where I will swap out the headlight and power distribution harnesses with ones that were in a 93 Explorer and see if that changes things. I feel like that's a pretty dramatic step to take here but other than pulling everything apart and checking the entire harness for shorted out wires and possibly ending up exactly where I am now, I'm out of ideas.
 

BlackBII

Ranger Custom
Article Contributor
OTOTM Winner
TRS Banner 2010-2011
Joined
Aug 14, 2007
Messages
7,364
Reaction score
117
Points
63
Location
UT
Vehicle Year
1989
Make / Model
Ford
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
4WD
Total Lift
5
Tire Size
33
Did you use the Ranger power distribution and headlight harness or the Explorer distribution and headlight harness?

Perhaps they are slightly different. I used the '92 Explorer power distribution and headlight harness. The only wiring on my truck that is original Ranger is the tailights and fuel pump.
 

adsm08

Well-known member
Supporting Member
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
31,638
Reaction score
1,018
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
Which climate control head did you use?
 

Shran

Junk Collector
Supporting Member
Article Contributor
V8 Engine Swap
Solid Axle Swap
Joined
Mar 4, 2008
Messages
4,250
Reaction score
89
Points
48
Location
Rapid City SD
Everything came out of the 94 Explorer except for the tail light and fuel pump wiring that starts right above the fuel filter, and the dome light and door harness. The thought of trying to reuse the Ranger under hood wiring to some extent crossed my mind but the previous owner hacked it to shreds and it was just not fixable.

The HVAC controls came out of the '94, have also tried '93 Explorer controls as well with the same results.
 

BlackBII

Ranger Custom
Article Contributor
OTOTM Winner
TRS Banner 2010-2011
Joined
Aug 14, 2007
Messages
7,364
Reaction score
117
Points
63
Location
UT
Vehicle Year
1989
Make / Model
Ford
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
4WD
Total Lift
5
Tire Size
33
This is quite the mystery champ.

Here's the diagram I have. The only way I see the blower knob adjusting the brightness of the dash lights is if the Orange/Black wire is connected to the dash lights somehow?

The blower motor doesn't turn on at all?

 

Shran

Junk Collector
Supporting Member
Article Contributor
V8 Engine Swap
Solid Axle Swap
Joined
Mar 4, 2008
Messages
4,250
Reaction score
89
Points
48
Location
Rapid City SD
That's the same diagram I have in my book, I have been poring over it tonight. I agree that the orange/black wire shouldn't be connected to anything other than the blower fan.

I thought the fan was not blowing at all, turns out that it is in fact ON, at one very slow speed, and doesn't get faster regardless of fan switch position although it does shut off when the switch is turned off.

Some thoughts:

- white/lt blue wire from the HVAC controls goes to interior fuse 9 (heater and AC control) but fuse 9 is connected to fuse 5 (turn, backup, DRL, heated rear window, blower motor relay, turn lamp relays.)

- @ blower relay, pink/white and orange/black go to the fan and through that same relay runs purple/orange

- purple/orange runs from there to the DRL module (or DRL jumper, which I have) and dead ends, but also is tied into the turn signal flasher and backup lamp switch

I believe that purple/orange was one of the wires I had to splice. I am using the automatic transmission harness with several wires removed that were for torque converter lockup and other stuff - anyway the black/pink and purple/orange wires are connected to the backup lamp switch like in the diagram. Reverse lights work, truck starts in neutral (although ONLY in neutral, the clutch pedal switch is not wired in at all.) FWIW the blower motor issue is still present in any gear so I'm not sure it's related at all.

I have also tried removing the blower motor relay and replacing it with a known good one in case it was fried, no change, and also adding a temporary test jumper where the relay was between black/light green and pink/white to eliminate power to the purple/orange wire completely. This resulted in no power to the dash lights and still no working fan blower.
 

Thighman

Member
Joined
Oct 3, 2007
Messages
159
Reaction score
0
Points
16
Age
32
Location
California
Vehicle Year
1990
Make / Model
Ford
Transmission
Automatic
Sent you a PM. Let me know if you want to talk. Not sure if my issue was that same as yours or not. Probably easier to talk through it.
 

bobbywalter

TRS Technical Staff
TRS Technical Advisor
TRS Banner 2012-2015
TRS 20th Anniversary
Joined
Aug 9, 2007
Messages
18,245
Reaction score
64
Points
48
Location
woodhaven mi
Vehicle Year
1988
Make / Model
FORD
Engine Size
BIGGER
Transmission
Automatic
My credo
it is easier to fix and understand than "her"
wrong ground or missing ground.


as in ground tied in.
 

Shran

Junk Collector
Supporting Member
Article Contributor
V8 Engine Swap
Solid Axle Swap
Joined
Mar 4, 2008
Messages
4,250
Reaction score
89
Points
48
Location
Rapid City SD
After many, many hours of searching and reading wiring diagrams, I think I have finally found the problem - I will know tonight when the dash is back in, but yesterday with just the harness in place, the dash lights work and the heater blower works perfectly and no longer controls the brightness.

The fix: Explorers grounding system is wired slightly different than the Ranger system is. In the Explorer, the blower motor, rear defrost, rear wiper/washer, and dash lights all share a common ground (#G200 as it is listed in a good diagram.) I eventually ended up reading that G200 is located on the driver's side under the kick panel near the parking brake pedal, on an Explorer. The equivalent ground on a Ranger harness is elsewhere, passenger side by the computer, I believe.

I never hooked up any grounds at all on the driver's side when I put the truck together.

So this led me to dig through the trash and pull out the wire bundle that started above the steering column in two plugs - one gray, one black, rectangular. Black one contains mostly tail light stuff. The gray one would have run towards the back of the vehicle and contains power windows, locks, speakers, etc AND a big black wire that is #G200!

I pulled out of the male Explorer plug, added it to the male Ranger plug that stayed with the vehicle (contains dome lights, door switches, etc) and grounded it. Boom, lights, heater, etc work perfectly.

This is the plug and wire in question (finished view of where it fits in the Ranger plug.)

 

adsm08

Well-known member
Supporting Member
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
31,638
Reaction score
1,018
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
That would make sense. If everything is trying to ground through another component that will turn it on when the circuit is activated.

I never had this problem because the two 4.0 setups I have built (only one has been installed to date though) were done with Ranger dash harnesses and Explorer engine harnesses.
 

Shran

Junk Collector
Supporting Member
Article Contributor
V8 Engine Swap
Solid Axle Swap
Joined
Mar 4, 2008
Messages
4,250
Reaction score
89
Points
48
Location
Rapid City SD
I think using a Ranger dash harness is the obvious easy way to go but the Explorer parts are now a good alternative, especially in situations like this where you need to add a major component (AC, in this case.)

This was an incredibly frustrating thing to deal with but I am glad that I was able to make it work and hopefully others will run across this issue and find this thread.

Thanks to everyone that gave advice throughout - much appreciated!
 


Top