2.9 to 4.0 wiring harness compatibility

[Jack-Is-Back]

Hi everyone, I’m currently swapping my 1990 Ford Ranger (2.9L 4wd automatic) to a 4.0l OHV. I’ve come to the realization that everything I got with the 4.0 when I bought it is for a 2.9 including the wiring harness. What years of the explorer wiring harness will still work? I also have my eyes on a wiring harness out of a 1994 Mazda b4000 4.0 OHV and curious if that one will work. Also I should note If anyone is selling a wiring harness I would be interested!

 

[sgtsandman]

I do know there are differences between a 2.9 and 4.0 wire harness, but I can't tell you what they are.

As far as which ones would work, we'll have to wait for someone who knows better to give you a year range on what would work. I think the B4000 is in that range but better to be safe than sorry. Other than different sheet metal, the Mazda truck is a Ranger in a certain year range.

 

[SenorNoob]

By the time the B4000 was a thing, everything under the hood had been rearranged. 90-92 Ranger 4.0, and 91-94 Explorer are the only harnesses that will have everything in the right place. Others can be made to work, but it'll be more difficult.

 

[bobbywalter]

what year is the 4.0?

 

[Jack-Is-Back]

what year is the 4.0?

Believe it’s out of a 91 explorer

 

[Shran]

Your best donor will be a 90-92 Ranger with a 4.0. Second best is a 91-92 Explorer. Some 93's will work, some have EGR & cam sensors like every '94. Making the donor year match your engine as close as possible is the main thing so that you're not adding or subtracting sensors and stuff.

The Explorer dash harness will work in a Ranger but it will require some modifications because of where the tail lights & fuel pump wiring are run through the interior instead of under the body like a Ranger. I used a 94 Explorer harness to 4.0 swap an 89 Ranger years ago and eveyrthing worked fine in the end but it was a lot of wires to splice, would have been a lot easier to find a 4.0 Ranger donor.