**** UPDATE****
After some checking found 3 things first tranny fluid was 2 quarts low didn't resolve the issue. Second MAF wasnt plugged in, plugged in and unplugged the battery for around an hour and didn't resolve the issue. Third issue which is the winner fuse 17 which controls all gauges and idiot lights.

Now when i put a new 10amp fuse in 17 it pops as soon as i go to start the rig and still has shifting issues. However, with the rig running if I change out the fuse it runs and drives perfect but if I try to restart the rig the fuse blows again. Could something under the hood be an issue since nothing inside was touched during this upgrade.


So my son threw a rod in his 93 F150 4x4 5.0 and instead of rebuilding the engine I had the brilliant idea I would do an engine swap from a spare which was a 95 f150 4x4 5.8. I took and swapped the complete motor/tranny/complete wire harness from the ecu to the heater/ also the tranny harness and pcm.

The truck starts and idles great moves forward and back fine.. However, the instrument cluster no longer works volts,oil,temp,volts. Also when i tried a test run never even getting down the block you cannot keep pedal in one position to say cruise at 10 mph or any speed it starts cutting out like it has no fuel.. Is there another module under the dash or harness i should have grabbed would a psom reset fix this(doubt full as i think thats only the speedo. Any tips would be greatly appreciated. I'm leaning towards i need a different harness under the dash and or the MAF i ruled out fuel pump and filter as the 5.0 and 5.8 use the same fuel pumps and filters

 

The general advice on the forum is to use the in the harness already in the vehicle whenever possible to avoid these kind of issues. But you are already down the rabbit hole.

One plan is to get a hold of the pin outs for the harness on each truck and compare them anywhere you hooked up the donor harness to the existing, and figure out where the mismatches are and re pin to correct the issue. This will not be great fun. It might be easier to put back the original harness, or transplant even more from the donor.

I had with problems with a harness transplant, even though it was the same year, model and engine, but different trim package.

 

The PCM gets it's speed input from the PSOM and vehicle speed is one of those must have inputs for correct powertrain operation, so you have to sort out the cluster problem. Have you tried swapping in the '95 cluster?

 

Thank you,, No I haven't tried to change the harness under the dash as that is no longer an option the truck went to the scrap yard to clean up the yard and they have already destroyed it.

Anyone have a suggestion where I could find the pin out diagrams for the different trucks

 

The Ford workshop manuals are available as CD's, and should have everything you will need. Sometimes the actual books show up second hand.

The info is also available through Ford as a web portal that you can pay to access for days, months or years. It is more complete, convenient, but spendy. https://www.motorcraftservice.com/Home/Pricing

Folks here on the forum can help you out as well, but you need to know what to ask for.

 

**** UPDATE****
After some checking found 3 things first tranny fluid was 2 quarts low didn't resolve the issue. Second MAF wasnt plugged in, plugged in and unplugged the battery for around an hour and didn't resolve the issue. Third issue which is the winner fuse 17 which controls all gauges and idiot lights.

Now when i put a new 10amp fuse in 17 it pops as soon as i go to start the rig and still has shifting issues. However, with the rig running if I change out the fuse it runs and drives perfect but if I try to restart the rig the fuse blows again. Could something under the hood be an issue since nothing inside was touched during this upgrade. Checking to see since everything i find in the forums leads to a short in the steering wheel but as mentioned nothing inside was touched and worked perfect prior to the upgrade

 

Yes. As mentioned below if the pinouts are different then you could be powering up a circuit that you shouldn’t be or have a higher current draw on a different circuit than intended.

You swapped out a 5.0 MAF for a 5.8 speed density engine, harness and computer? What transmission is in the ‘93 and what transmission was behind the 5.8? Also, you didn’t answer his question about reinstalling the original engine harness.

 

Everything is 5.8 now except the harness under the dash the motor, tranny, air cleaner, harness, a/c line wiper motor. Just did a straight swap. The original harness will not plug in to the ecm/pcm uncertain of its actual name (box on the drivers side firewall by the kick plate) as it has a different connector, also it doesn't have the O2 sensor connectors the 5.8 has 3 of them vs 1 on the 5.0

I'll reach out to my local ford tomorrow and see if they will give me a couple diagrams for the harness pins.

 

That doesn’t make sense to me. 1993 and 1995 should both have the same 60 pin connector. Does the donor truck have a 104 pin connector?

 

Here are photos of the two plugs

 

Good luck! You are going to have a heck of a time sorting it out if you don't know what you have.

Edit - I would stop running the truck until you get it sorted. You are likely to burn something up... which is what the fuse is trying to stop you from doing.

 

Oh boy. The larger 104 pin connector is EEC-V and an OBD-II system which is completely different than the EEC-IV system that was in the ‘93. That also means the donor truck was more than likely not a ‘95 but was actually a’96. All you had to do was replace the 302 with the 351 and plug it into the ‘93 wire harness.

Someone on here did a swap to OBD-II. I suggest you do a search to see if you can find his thread. I hope your good at wiring and electrical systems.

EDIT: The topic of installing OBD-II into an OBD-I truck might have been in one of the Stinger Performance threads. I’m not sure

 

Okay didn't even think of that. So I put the main harness and tranny harness from the 5.0 back on with the 5.0 pcm.

Do I need to use the actual engine harness from the 5.0 or is the one on the 5.8 compatible? Because right now it cranks but won't start


Think I may have figured out i will need to change the engine harness because right now it has two MAP sensors one that is on the 5.8 and the one on the firewall for the 5.0 even though only one is plugged in. Guessing it has a different set of pins that connect into the main harness even though it fits

Also not sure if the fact the 5.8 had a MAF and 5.0 didn't is going to make a difference providing the engine harness can even swap across

 

All you needed to do in the beginning was swap the engine. No swapping of any wires.
It's not that the 5.0 vs 5.8 differences, its the fact that you used to have a Speed Density (SD) truck, and your trying to swap in a Mass Air Flow(MAF) system, without actually knowing that.

No, not likely. One truck had a MAP sensor on the firewall, the other truck had a MAF sensor near the air filter intake box.
Did you get the MAF sensor from the donor truck, or is that gone as well?

Harnesses are different, plugs may be the same, but one is sequential fire, and one is batch fire. Pretty sure they are not 'plugNplay'.

 

Yes. Use the 5.0L engine harness. No the 5.8L harness is completely different. That was stated in post #2.