4.0 / m5od swap questions

[jtaborsky]

I am in the middle of a 4.0/m5od/m1354 swap from a 1992 Explorer to my 1987 Bronco II and have a few questions.

1. The speedometer cable is too short now. Is that something that has been encountered by anyone else? Do I need the speedo cable from the donor vehicle? Do the 1st gen explorer gauges use the same speedo cable as the 1st gen Rangers/Bronco II's?

2. Where do the fuel pump wires come into the engine bay on a 1987 Bronco II? I have the fuel pump wiring correct to where the ignition switch powers the fuel pump relay, which delivers powers to the pink/black wire from the Explorer's fuel pump circuit. I just need to know where to send power to the actual fuel pumps.

3. I have a few wires coming from the power distribution box on the passenger side that I am unsure of. The colors are as follows (primary color/trace color):
yellow/light blue
black/white
dark green
black/light blue
dark green/yellow

I am sure I have left out necessary details on the issues. Please ask for clarification.

Thanks for all the help!
- Joe

 

[neggen32]

Are the wires from the power distribution box going to a plug or harness or are they just cut off near the bottom? As long as the thick black cable from the power dist box is connected to power and the 4 pin plug from it is connected to the 4.0 harness, you should be good. That plug powers your fuel pump and eec relays, and the only fuses you need for them are a 30A fuse in slot one, and a 30A fuse in slot 8. In the donor vehicle those other wires just went to stuff like the headlamps, blower, door locks, defrost, and other random fused things that you shouldn't need with your swap. You can now use them as a way to get fused power to your own accessories which is pretty cool. I just posted a swap write up in this forum, check out the section on the power distribution box. I used the fat green wire in my swap as a way to connect the alternator to the battery and tossed a 60A fuse in slot 10.

EDIT: I misspoke, actually used the fat green wire as power to ignition.

 

[neggen32]

Also, on my 87 Ranger there is a small grey circular 1-pin connector on the wheel well near where the fuel lines come up, should have one Pink/black wire in it. This sends power to fuel pumps

 

[jtaborsky]

I read through your write-up last night, but I was confused as to why you didn't just use the 4.0 alternator to simplify wiring. The mounts were completely different between my 2.9 alternator and 4.0 alternator.

I used the thick light green from the fuse block as the main ignition wire, as is shown in my chilton.

Are the fuel pumps chassis-grounded? Does the wire near the fender split off to power both fuel pumps? Is the sending unit wired directly to the gauge?

Thanks for the detailed response.
- Joe

 

[neggen32]

I'm sorry, you're right about the alternator thing. I am using a 4.0 alternator, but the previous owner spliced it into a 2.9 alternator harness for some reason so that is how I had to wire it up. Using the 4.0 alternator and harness is the best way, and the green wire on the distribution box is power to ignition as you said, when spliced to the blk/orange wire. That was the only part of my write up I was unsure about so thanks for bringing that to my attention, just edited it.

As for the fuel pumps, they are chassis grounded. If you found the single wire fuel pump connector that I described, yes it does split and power both pumps. However, another user found a different 7-8 pin connector in the same spot with 2 fuel pump wires in it, but I think that's just because his '87 has the dual tanks. Here is what he said if you have the same thing:

"If you look down on your frame rail by your fuel filter you will see a connector that has about 7-8 wires in it, these are for your tailights, fuel pumps, etc. on the 2.9. Cut This connector off and find the*BLACK/PINK*wire and*RED*wire. The Black/Pink wire is power to your High Pressure In-Line pump and the Red wire is power to your in-tank pump. Connect*BOTH*of these wires to the*PINK*wire on the 4.0 Harness."

The sending unit for the fuel gauge is wired directly to the gauge and I didn't need to touch it with this swap. I think it's a yellow/white wire if you're curious though

 

[Kurt.king870s]

I'm not certain, but I think the speedo cables are different on the transmission end. When I pulled that end out of the trans of my 94 2wd, the cable pulled out of the gear in the trans, but in my 88 4x4 the red gear came out with the cable........but that could be a 4x4 or 2wd thing, not sure. I think the gauge ends are the same though.

 

[jtaborsky]

Well, I found the fuel pump wires. Very close to what you were describing, neggen. It was a harness with two wires going to a single pin in the location you described.

I think I have my speedo issue worked out as well. I found the cable from the donor vehicle, and I can't imagine why it wouldn't work.

My next hurdles are getting the fuel lines adapted, getting the driveshaft shortened, and finding some weatherproof connectors for a permanent solution for the splicing.

Thanks, everyone, for all the help thus far.
- Joe

 

[neggen32]

Nice! Soldering and shrink-tubing is definitely the way to go for the splicing, and it's pretty much waterproof. Unless you think you're going to want to disconnect the wire at some point

 

[jtaborsky]

I want to leave myself the option of disconnecting the wires. I can't imagine how or why it will come up again, but if/when it does, I want it to be easy!

- Joe