truck converting to 4x4:
1996 F150
-302
-e40d
-OBDII

Donor truck:
1994 F150 4x4
-302
-4r70w
-OBDI

Problem:
We installed the 4r70w trans + t-case in the 2wd last night. Everything went smooth and bolted up but I got one problem now. The wiring for transmission is different. We took out transmission harness out of 4x4.

Question:
Both truck harness's are connected to two plugs on drivers side inner fender close to firewall.
The E40D has 3 plugs on harness: 1. 02 sensor
2. Gear selector ( Drivers side )
3. On top of pan ( Passenger side )

The 4R70W also has 3 plugs : 1. Gear selector ( Drivers side )
2. Two prong half way up ( Drivers side )
3. On top of pan ( Passenger side )

Could I make the 4x4 Harness work some how on my 1996.
If So does ANYONE know what to do?

I've been talking to 1 guy on www.f150forum.com . But I would like some one else's opinion on this. I really want to keep this transmission set up as the Transmission was just rebuilt.

Here's the link to our Conversation. All this work for nothing? please help! - Ford F150 Forum - Community of Ford Truck Fans

Any Help would Be great!

Thanks,
Colby

 

I am a little bit confused - how many O2 sensors does each truck have? I thought 96 and 94 302s would both be OBD2.

My truck is OBD1 so this may not work but all I had to do was plug in the trans harness from the donor truck into my existing underhood harness.

If the donor truck is truly OBD1 you are going to have to either convert your truck to OBD1 or you are going to have to find the proper ECU because the ECU for the E4OD is not going to work with the 4R70W.

 

96 was the OBD1 cutoff, they switched to OBD2. I think the mistake was to have a donor truck with a trans from one model, and the project truck another.

I have seen people with Hondas get OBD2 computers then cut and splice wires together to retrofit an OBD1 system into an OBD2.

If I were the OP and had to go off where he is at now, I would probably run a few extra wires from point A to point B to get done what I needed. It seems as though the 2 harnesses are too different to make this an easy conversion. Anything can be done. The question is how much work do you want to put into it?

 

Yeah Im sure I can make something work. I wonder If I went to Ford and ordered a transmission harness for a 1996 4r70w 4x4 it would just plug into my exsisting harness?? Im so bummed out right know I got all my parts ready to go into truck but now the trans issues just stumped me.

Also where is the ECU located in my truck? If I went to a wrecker and for a 96 with the 4r70w transmission then I would be golden right?

I dont know... I just need help with this bad. Im going to call the transmission shop and auto wreckers and ford tommorow and try and figure this out.

but thanks for the help guys! really appreciate it

 

IMHO the safest bet is to get an OBD II transmission of the correct year for your project.

Which particular computer came installed in any particular vehicle is determined by the Calibration Code - 49-state emissions or California, low or high altitude, AC or no, what engine & tranny, what axle ratios, etc. etc. etc.

There are literally hundreds of such Calibration Codes.

You may be able to get a standalone aftermarket transmission computer, I know they're available for the E40D so I'd guess they should be available for the 4R70W.

But it's gonna be pricey, expect to pay around $1,000 for the computer & adapters & necessary hardware.

You should also be looking at the colors of the wires in the plugs, it's probably not as simple as merely plugging in two connectors.

 

Hey thanks for the input.

The wires on the two harnesses are pretty much the same, 6 in one plug and 15 in the other on each harness just the 2 ends are diffrent. Im going to call around tommorow and see what I can do. If worst comes to worst Ill pull the transmission out again. my buddy has a 89' 302 5 speed with the manual transfer case for $500.00 and come with a parts truck. Am I going to run into the same problems If I just convert the truck to 5 speed?

 

I honestly don't know, but it wouldn't surprise me if your computer had issues with no longer having a transmission to worry about.

I'm assuming you're referring to a manual tranny for the 5-speed, right?

 

With something like that id look at it the way they do when someone does one of those Ford-Cummins conversions. Use the old mechanical diesel with a newer high tech trans. What they end up doing is getting a standalone computer for the trans. This would be the same case only instead of a trans computer you would get an engine computer. That way the trans is excluded from the computer and you wont have shift problems and whatever.

I would do what you said and go to Ford or something first and see if you can get a harness for the application you are looking for.

 

Can you convert your '96 truck to the OBD1 system of the '94?

 

The eeasiest thing here to do is convert to a manual in my opinion. Besides the obvious, you'll jsut need a ecu from a similiar model truck with a manual tranny. Plug and play. Using an ecu from an auto trans equipped truck will cause issues as the ecu is trying to send and receive signals from the trans, where as a manual trans ecu has those lines taken out. Hope that makes sense.