1990 Bronco II >>> 1992 Explorer 4.0 Swap Question

[Suwanee Broncos]

I just posted this at the Corral, but thought I may catch more traffic here.

My son's first truck/ project is a 1990 BII. It's been swapped to the Mitzi 5 speed. The 2.9 gave up near instantly, I purchased a running and driving 1992 Explorer 4.0 auto. The engine has been swapped into the BII, the engine harness has been pulled from the Explorer and installed into the BII. All connectors have been matched up. We cut the harness at the underhood fuse box and have rewired things there accordingly.

NOW... I get mixed information that varies by year of donor and year of recipient on what re-wiring needs to take place. Does anyone know firsthand on this specific combination what gets changed? One source says that it's plug and play on a late 1990 model, while others follow the chart from Corral/ TRS (which doesn't seem to match my wiring colors.) The Chilton manual is pitiful and of little help.

I'm pretty competent with engine electrical and know my way around the Bronco II/ Ranger pretty well. I've owned about a dozen of them, currently have a 1987 BII that I 302 swapped. I've lurked here and even joined under a couple of names over the past 24 years. (My first truck was a 1998 Ranger and I lived on TRS)

Just looking for information or confirmation before we put a battery on.

Thanks!

 

[SenorNoob]

90 B2 has the Big White Plug (Round) near the steering column doesn't it? That's the only connection I'm aware of for that swap.

I'd pull the 2.9 harness beside the 4.0 one at that point and compare wire colors and pinouts. There are probably very similar if not the same.

 

[Suwanee Broncos]

Yes, it has the "BWP." There are some who leave that alone and just dice and splice at the big fuse box on the passenger side. That's the instructions that I followed.

 

[Shran]

I probably would have used all of the wiring from the Explorer (dash, headlights & engine harness anyway) and spliced it into the B2 body harness. That's what I did when I 4.0 swapped an 89 Ranger a few years ago. That's just my preference I guess - IIRC Explorer harnesses are very similar to B2's. The annoying thing about using the Explorer harness in a Ranger is that the fuel tank and tail light wiring doesn't run inside the cab like it does on the Explorer - more splicing to do in the engine bay.