2.3 to 4.0 wiring issues and questions

[94Reborn]

I am doing a swap on my 94 ranger. It came with the 2.3 dual ignition and a manual trans. I am installed a 93 explorer 4.0 ohv and a 92 ranger manual trans. The wiring between the explorer and ranger are similar but slightly different. I have what I would call the "power distribution" portion of the wiring harness still installed in the truck, including the headlights lights, blinkers, MAF plug, etc, all the way up to the bulkhead connector. There are four plugs that were disconnected for the 2.3 removal, 2 round and 4 big square ones all near the drivers side firewall, all running to the engine. The engine harness that came with the explorer seems to just have 2 round plugs and they are on the other side of the engine. I went to the junkyard and got an engine harness from a 95, if I remember right, ranger with a 4.0 and manual trans. I grabbed the ecu and the engine wiring from this truck. The two large square plugs match right up, the bigger of the two round plugs match up (this one is grey in color), but the smaller round plug doesn't match. I'm not sure what it runs to, but I think it's either for the transmission or the oil pressure sensors. It's a 2 or 3 wire plug, I'd have to get over to the truck to double check. The plug is black on the outside but red plastic on the inside. So I guess my question is, did anyone else run into this problem, and can I just splice these wires in somewhere?

Also, an even more important question, is I don't know where the EDIS module would plug in. The engine harness I grabbed from the 95 ranger doesn't have a plug for it, and the existing power harness on my truck doesn't have it near the radiator where I've read it goes, because on my 2.3 it was mounted to the motor. Do I need to replace the entire "power" harness on my truck with one from a 4.0? Or can I just splice in the EDIS module to my explorer/ranger hodgepodge?

The guy I bought the engine from gave me the power harness and engine harness from the explorer that runs all the way to the big round bulkhead firewall plug, so I could swap the entire thing over. But the idiot cut it all up and it would be quite a challenge to splice it all back together again. And at that point, would the bulkhead connector even match directly to the one in my firewall?

I know this sounds confusing and probably isn't explained the best way possible, but this is my first complete engine swap, so I'm a bit in the dark. I'm decent with electrical work, but this is a bit overwhelming for me. I read the big 4.0 swap article on this site, and read up on how the EDIS and DIS differ and how they function, but I was unable to find anyone explaining how exactly to wire it in. I know this was long winded, sorry about that. But does anybody have some pointers? Thanks.

 

[AlaskanRider]

I think your mix and match of years might give you trouble. The injectors changed 93-94 era (not sure which). A computer tuned for later injectors might not work as well on earlier injectors.

My 92 explorer and 90 ranger 4.0's both had their EDIS modules located near the heater's blower motor.

The explorer harness is different than the ranger harness.

 

[94Reborn]

How are the injectors different? I went to the junkyard and grabbed the entire underhood wiring harness from a 94 with a 4.0, including the edis, power distribution box, and entire engine wiring harness. So I should be able to plug and play as long as the bulkhead connector matches up. I haven't heard anything about the injectors being different.

 

[xkotyx]

I'm in the same swap at the moment. Use the ENTIRE explorer harness. The only difference should be at the firewall connector (which I just posted a thread about asking for the wiring diagram for that) lol

 

[94Reborn]

I'm going to run the 4.0 ranger harness because the explorer harness is set up for a battery and relay box on the passenger side and mine is on the drivers side, and the guy who pulled the motor cut it all up. And I'm hoping the firewall plug will go together without splicing since they are both from a 1994. I got the engine set in place last weekend and hope to tackle the wiring this weekend so I'll post back on how it goes.

 

[xkotyx]

I changed my route. I didn't wanna take a chance with the firewall connector so I ended up pulling the dashes and running all explorer wiring

 

[Roger]

Since we are starting to tear into our own 90 Ranger 2.3 swap for a 94 Explorer 4.0, we decided early on to just swap everything. We wanted to have cruise control and AC in the Ranger and eventually have power windows/locks and mirrors to, so a complete wiring harness is being swapped over as well. We just drove the Ranger into the garage 30 minutes ago and have started stripping it. Good luck with your swap!!!

 

[94Reborn]

Ok I got most all the wiring completed, I used the full harness from a 94 ranger 4.0. I only have 2 questions. Question one: There is a small round black 2 wire plug with red plastic on the inside of the connection, located near the power distribution module and main harness plugs. It is coming off the piece of harness feeding the ac compressor, alternator, and crank sensor. I don't have anywhere to plug it into, and can't remember if it was plugged into anything on the junkyard truck. Anybody know what this plug runs to, and if it needs to be tied in somewhere?

Question two: There is another 2 wire plug I'm not sure where to plug in. It is coming from the power harness with the headlights and all strung off of it. The plug in question is in the area behind the drivers headlight, and comes off the main bundle around the same point as the horn power wire. There are 2 places it could plug in, one is coming off the power steering box there seems to be a pressure sensor that is two wire I don't have plugged in yet. The other is a two wire sensor on a vacuum line running from the intake to the vacuum canister by the drivers headlight also with nothing plugged in yet. These are the only things left not plugged in so I would assume one of these gets plugged in and one is not used. Anybody know which sensor gets plugged?

Other than that the wiring is done. I'm bolting the headers on this weekend, then I just need to drop the radiator in and flush all the fluids and see what happens.

 

[94Reborn]

I think I answered the second question for myself. Looking online it seems the power steering pressure sensor was only applicable for the 2.3 ranger, and the v-6 does not require the low idle sensor. I still need someones opinion on the black and red round plug though!

Also I'm thinking the black plug with the red inside is the air conditioning high pressure switch plug. Apparently they are in different locations between the ranger and explorer. Would anyone be willing to unplug their ac high pressure switch and see if the connector is red inside and a round 2 wire plug? Pretty please!

 

[94Reborn]

Update: I sorted out the wiring. The plugs were what I thought, a vacuum regulator and an ac high pressure sensor. Unfortunately I snapped a header bolt trying to install on the drivers side so I have to take it to a shop and have a nut welded on the exposed stud. I think there was some crud inside the threads on the head because nothing wants to back the stud out. Other than that I'm finished minus the fluid changes and putting the hood back on. I can see the light...

 

[Roger]

We're close to being done with our 2.3 to 4.0 swap. All thats essentially left is swapping the rear axles and springs. And then just button things up and get it registered. Good feeling when you get close to the end of a project!!!

 

[94Reborn]

Seeing the end in sight does feel good! I've got mine almost finished. It's at a muffler shop now having the broken stud removed and the rest of the exhaust welded up. After that all that's left to be done is to flush and fill all the fluids and bolt the ac compressor and starter back on. I'm doing that tonight after it gets back from the shop so I should be able to crank the thing over tomorrow.

 

[94Reborn]

Got it started! It didn't crank the first time. I checked the battery and it was bad, and I went ahead and added an extra ground cable and new terminals and swapped the battery and it fired up on the second crank. Ran pretty good but my fuel pressure regulator is spraying out at the line connection. Hopefully I'll fix that and take it on a test run tomorrow.

 

[AlaskanRider]

Congrats! The more random cars I drive from that era the more I appreciate the 4.0. Torquey, and power that comes on fast! Kicks the snot out of my 80's v8 chevys, and does 4-6 mpg better. I was so pleased with myself when I finished my swap.

I can't remember the physical injector difference, someone told me that there were changes around that era, and If i loaded a tune for a 94 onto my 92's computer, it wouldn't work right with the injectors.

Hopefully not an issue on your truck. I got pretty lucky with compatibility on mine. Ive got such a mix-match of stuff on my truck, its rediculous. 2.3 2.9 and 4.0 stuff all mashed together with a 4 year window.

 

[94Reborn]

The truck runs pretty well but I have a strange problem with the cluster gauges and a check engine light. I posted in the 4.0 section of the forums with details, but my oil pressure gauge shoots up and my battery gauge shoots down when I turn my headlights on or any other electrical load is applied, but the voltage stays at 14.3 when running. Also the CEL is for an ECM power interruption. I've checked the grounds and voltage at the battery but now I'm stuck.