Explorer OBD2 Harness Re-work

[Turningwrenches]

I need a 97 explorer 5.0 harness and computer done Gary. I sent a email and never got a reply. only need engine and fuel system to work. Will be using a manual transmission. Thank you.

 

[RM70]

millerpz gave a great answer, but I'll expand on it just a bit.

If you are not running a 4r70w and you don't have the transmission harness, you will need to find a green o2 sensor plug to add to your engine harness.

It's also a good idea to run a VSS with a manual transmission, but it's not 100% required. The OSS plug from a transmission harness can be used for it.

The rest of the wiring going to the transmission can be removed.

The engine/transmission harnesses together don't have to be modified at all, but you will be left with a bunch of extra plugs and wiring if you don't. All that really happens to the engine harness is moving an o2 sensor plug from the transmission harness to the engine harness, the rest is just removing unused wiring.

Post #2 gives PCM pin numbers of every circuit that can be removed.

Glad I went through this thread. Was watching the videos when I realized I didn't have the transmission harness but looks like I don't need it since I'm using my C4.

 

[Dtorres10312]

Hello! So glad I found this page! I recently bought a 92 ford ranger rock crawler that the previous owner did the 5.0 swap; he got the donor motor from a 97 mountaineer. The previous owner literally ripped out the old ranger harness and replaced the entire harness with the mountaineer harness. Im wanting to clean up the wiring as there is a ton of wiring not being used. Im running a m5od r2 transmission, Atlas 2 transfer case. Its a dedicated rock crawler. I want the bare minimum wiring! Can anyone point me in the rite direction! Thank you!

 

[DirtDonk]

Hey Dtorres, welcome to classicbroncos. Sounds like an interesting vehicle for sure.
Sounds like he's backed up, but I bet he can do what you need, especially since you have a harness he can work with already.

Good luck.

Paul

 

[Jedeka]

Dtorres, if you have a mechanical mind, I suggest watching Gary’s YouTube videos. If you just want to eliminate extra wiring, he does a good job in the videos, explaining what each wire does in the C115 connector. Eliminating them is pretty easy with a small, flat blade screwdriver.

 

[WindVeil]

All, I want to start my own thread but haven't built the skills on here yet.

Short bio, I bought a 99 Explorer, stripped it put engine and trans in my 68. Took the complete wire harness out and laid it in my Bronco and plugged it in to do a test start.

Key is taped to the security thing, theft light flashes and goes out.

My 2013 23 gallon tank was refit with Explorer pump, line that goes to evap, and other connector.

Slide the Explorer ignition switch to start but nothing, fuel pump doesn't even come on.

Hot wire to fuel pump and it works but no starter, hot wire to starter too and it cranks perfectly.

What would stop current from the starter and fuel pump? Inertia switch was reset, tried that first. Plugged evap wires but not the line from front to back.

Thoughts?

 

[DirtDonk]

Inertia switch should effect the pump only I would think. But with the lack of cranking seems like it could be a couple of things. Bad neutral safety switch (is yours connected?) bad ignition switch maybe.
No pump. Bad ECU, bad ignition switch, bad fuel pump relay, busted wire or connection?

Are you sure that having the key taped to the thingy is enough to disable/fool the anti-theft system? Is the key battery operated? If so, could the battery be dead? Sounds ok since you say the security light goes out, but just spitballing here and not really sure of all the things that might be different with a factory harness.

Good luck. Oh and starting a new thread is actually pretty easy. If you decide you want to, we can walk you through the initial steps. Posting it here like you did may still be the better way to get a quick answer though.

paul

 

[WindVeil]

DirtDonk thanks for the reply. I thought inertia switch at first since I just self tap screwed it to the fresh air panel on the passenger side. I took it off flipped it over until it clicked then reset it. No change.
I'm using the Explorer switch I took off the Explorer column, it's just a slide handle but hits all position ACC, run an start. Lights in dash come on but again no power to starter or fuel pump. The Bronco dash is out I just have the Explorer dash plugged in so I see things working, rpm, heat, oil pressure, battery and check engine light. Just for testing. Maybe I need to get my ignition switch off the Bronco dash and try to wire it up, just not sure what the change would be, ground maybe?
I drove the Explorer up to the day I took the engine out 2 months ago so everything was working.
Today I will go to my backup key just to check, but I'm thinking I read somewhere that evap would stop it from running if it can't pressurize the tank. I remember something about putting a 5 ohm resistor in the pink and black wire going to the tank, I will go through and try to find it again and figure out how to install it. I have the link for posting pics so I may look that over and see if I can start my thread.

 

[garberz]

WindVeil, I think you should send your ECU, (2 of them) to EFIGuy and have him flash them for what you are currently set up with. That will simplify things and you can get rid of all these things you're trying to work around. It would be much easier to troubleshoot when something else pops up.

Mark

 

[WindVeil]

I think you are right, I did message him and he said it should crank as long as I have the key but the troubleshooting is going to kill all my time.

You said 2 computers, are you saying I should find another and have it done as a backup?

Update:

Switched the key to the spare and instrument cluster gave a fuel reset message. Inertia switch was triggered so I reset it and the fuel pump is now cycling like it should. Still no starter but I think DirtDonk is on to something with the neutral safety switch. I'll play with that next.

 

[garberz]

I always have Garry do two for each build. I just like having a back up, because it's a one-off part that really can't be sourced anywhere else.

Mark

 

[toddz69]

I always have Garry do two for each build. I just like having a back up, because it's a one-off part that really can't be sourced anywhere else.

Mark

I did the same with my harness build - had 2 computers configured. Every time I walk past a '96 in the yonke, I think of grabbing it and having a 3rd burned!

Todd Z.

 

[betzgb]

I am using the EFI Guy recommended small fuse box for the power distribution to the PCM, O2, Coils, and fuel pump. I have a donor harness from a 96 Explorer. Two questions:

1.) What size fuses are you using for the 02 sensors? Ignition coils? I used 20 amp for the fuel pump and the PCM.
2.) The fuse box is mounted on the driver fender well and battery is in the stock location . I have about 11 feet of 10 awg feeding the small fuse panel. According to a site online, 10 awg should handle 20-35 amps. What gauge wire are other people using to connect that small fuse box with? Do you fuse that feed also?

 

[NBraun]

This is the most in depth source I have found for the explorer harness! Thanks for taking the time and effort to share this information freely.

Now I hope you don't mind me asking some questions.

I'm swapping a 97 explorer motor and harness into a 1994 obd1 2wd ranger. I have the whole donor vehicle, so I was hoping to use whatever I could off of it to save costs. It seems like the harness rework is just so it looks cleaner, but it's not necessarily needed.

I would just like to verify my thoughts before I start doing anything. I honestly don't care if the harness looks a little messy, therefore I don't think I will bother removing plugs, etc. I don't Plan on keeping Evap, EGR, rear o2's and the truck never had A/C, so I won't keep that either.

I'm a little confused on what I would "Need" to do Just to get it to run. Assuming I just cut the c115 plug off the explorer, then de-pin it to keep only the wires I would need. I would need to splice in from the ranger harness, Power to Pin 9 from the relay. Power to the fuel pump, from the relay, pin 15, and 5. Power to pin 1 for the coils. Lastly power to pin 36 for the 02 sensors.

I know the general consensus is to send the PCM off to you to get retuned, this is a challenge car, and I don't have a huge budget. If I don't get it retuned, what will happen?

Please tell me if I'm being dumb, or missing some huge thing.

Thanks!

 

[sarens]

ok had Garry program my PCU, I stripped out harness to make stand alone engine harness, running M/T, no EVAP, no EGR

-have everything hooked up, no spark, beginning to believe I took something out that I should not have

-anyone have a pin out of the PCM plug with descriptions?

 

[DirtDonk]

So it cranks but no fire?
You've verified that there is no spark at all, but you're for sure getting fuel to the injectors?

What about any relays, such as the one for ecu power? Maybe test those to make sure they're doing their job. Seems like a bad power relay could keep it from sparking.

Good luck.

 

[chuzie]

Does anyone have decent wiring diagrams for both 98 and 2001?

After my fire, I'm now attempting to put a 2001 engine and trans harness on my existing 98 setup, so looking to verify color and pin variations.

Thanks.

Sent from my SM-G781U using Tapatalk

 

[bsquared]

Does anyone have decent wiring diagrams for both 98 and 2001?

After my fire, I'm now attempting to put a 2001 engine and trans harness on my existing 98 setup, so looking to verify color and pin variations.

Thanks.

Sent from my SM-G781U using Tapatalk

Hi Chuzie,
I do not have any wiring diagrams for those years specifically, but I did download a PCM pin diagram that someone had put on the site. It helped me when I was doing my harness. I can also add the sheet I made detailing Garry's description of the C115 connector wires and which ones can be removed. Hope these docs can help anyone doing this harness work.

 

[chuzie]

Hi Chuzie,
I do not have any wiring diagrams for those years specifically, but I did download a PCM pin diagram that someone had put on the site. It helped me when I was doing my harness. I can also add the sheet I made detailing Garry's description of the C115 connector wires and which ones can be removed. Hope these docs can help anyone doing this harness work.

I'll take anything. It all helps. Thanks

Sent from my SM-G781U using Tapatalk

 

[bsquared]

I am using the EFI Guy recommended small fuse box for the power distribution to the PCM, O2, Coils, and fuel pump. I have a donor harness from a 96 Explorer. Two questions:

1.) What size fuses are you using for the 02 sensors? Ignition coils? I used 20 amp for the fuel pump and the PCM.
2.) The fuse box is mounted on the driver fender well and battery is in the stock location . I have about 11 feet of 10 awg feeding the small fuse panel. According to a site online, 10 awg should handle 20-35 amps. What gauge wire are other people using to connect that small fuse box with? Do you fuse that feed also?

Hi Betz,
I fused my PCM at 30 amp, fuel pump at 20 amp, Ign Coils at 25 amp and the O2 Heaters at 15 amp. I ran #4 AWG to the fuse box because I had the wire and lugs for it. It has a 175 amp Bussman megafuse between it and the battery / alternator buss. I really should reduce that megafuse to about 80 amps, just haven't messed with it yet.

For what it's worth, I also used the small fuse / relay box that the EFI Guy sent me and I just plain sucked at building it. (no ding on Garry, it was just me sucking at it) Almost got stranded in the middle of Nowhere, TX, from the power wire pulling off of the fuel pump relay and getting fried. Luckily made it back to base camp and decided I needed an upgrade.

Someone suggested the Bussman 15303-2 fuse box and that is what I went with. It has 2 internal busses, one that powers the fuses from the battery / alt and the other that I used to power the #30 pin of the relays when in run / start, where the diode goes. I know these pictures look real busy, but it's actually pretty simple to build out. It and many of the connectors can bought from a distributor called Waytek. It is expensive to get tooled up and get the connectors, but it gave me peace of mind when I'm crawling in the middle of nowhere. If your build skills are up to snuff in the small box, then it should be fine, just thought I would share. Good luck on your build! B2