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Discussion Starter #1
I’m close to sealing the deal on a 65 fastback with a 5.0l conversion but the engine bay has me a bit turned off. The car runs and drives great, with enough power for weekend cruising, but I’m wondering what I could possibly do with the wiring job.

The current owner performed the engine swap and purchased an aftermarket wiring harness (I believe he said Ron Francis??) but I’m a very detailed person and the engine bay doesn’t cut it for me. As for the wires, fuse box, and relays mounted to the passenger side engine panel, can these be relocated to somewhere in the interior and still function as intended? Where have others that have done this conversion mounted and routed their wiring/fuses/relays? What are my options with this setup to clean it up and make it more presentable?
 

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Ron Francis is a well known wiring supplier. You could relocate the fuses and relays ect .sure,all it takes is more rewiring. Personally I'm not a fan of the Fox body look under a vintage hood. And the front timing cover dress and belt driven accessories
 

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Discussion Starter #5
I routed a lot of my wiring behind the engine on the firewall or under the dash. There are some wires that have to be in the engine bay, but all of the relays can be relocated under the dash. A lot of other wires can be routed more discretely as well.
Nice looking engine bay! Do you have pictures of how/where you routed the wires and where you mounted the fuses, relays, etc? Thank you!
 

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I don't have any pictures but essentially mounted the computer and relays under the dash near the center. I used James W's mustang site for a lot of the swap. I retained my stock fuse block and ran inline fuses when needed.
 

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It's a tight engine box for all the 5.0 EFI business. The biggest issue is the huge harness from the intake to the ECM, and I hate all the stuff they tied to the starter solenoid! Mine is a driver and utilitarian underhood. The neat and tidy route will require alot of wiring and sacrificing room elsewhere. I like the use of the crossflow radiator, my donor didn't have one. Good luck!
 

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Discussion Starter #8
It's a tight engine box for all the 5.0 EFI business. The biggest issue is the huge harness from the intake to the ECM, and I hate all the stuff they tied to the starter solenoid! Mine is a driver and utilitarian underhood. The neat and tidy route will require alot of wiring and sacrificing room elsewhere. I like the use of the crossflow radiator, my donor didn't have one. Good luck!
Got pics of your engine bay? Whether it’s good or bad I just want to get ideas of how others have their conversions setup. Thanks!
 

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Discussion Starter #10
Here’s mine. I would call it working functional. Easy to get to everything Without looking a a rats nest of wires and relays
Well done - looks good to me! Where did you mount your fuses, relays, etc?
 

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All are on the right side apron. The cold air intake is in the way if you need to get to the headlight relays which are in the old battery area. The relays for the efi harness are on the rear apron. I’ve never had an issue but the car doesn’t see rain or snow.
 

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Discussion Starter #12
All are on the right side apron. The cold air intake is in the way if you need to get to the headlight relays which are in the old battery area. The relays for the efi harness are on the rear apron. I’ve never had an issue but the car doesn’t see rain or snow.
Thanks for the info! Assuming you completed the conversion using an aftermarket harness and wiring kit, were the supplied wires too short to route into the interior of the car or did you decide to keep everything in the engine bay due to convenience of installation? Just curious so I know exactly what to expect should I decide to purchase the car and reword everything to reach the interior.

If anyone else has more pictures to share please post!
 

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As I recall, the harness was set up for the efi relays on the apron. The only thing I have wired inside is the computer. I think you would have to rework the harness to get more components inside the car.
 

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All it takes is some wire, connectors, shrink tube, solder and patience. You can buy screw-together bulkhead plugs to run the harness through the firewall or apron to the kick panel, glove box area, etc.

If you want to construct your own harness, measure the wire runs with scrap wire or string and lay everything out on a sheet of plywood with screws or hooks to route the wires, then wrap it and install.
 

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Got pics of your engine bay? Whether it’s good or bad I just want to get ideas of how others have their conversions setup. Thanks!
Mine is definitely a driver. I wanted as close as possible to the fox setup for simplicity of repairs and surprise factor. No attempt was made to hide the "busy" starter solenoid, just like the fox underhood. ECM is under carpet on trans hump. The strut tower brace had to be clearanced for the intake elbow and keyholed for the EGR vacuum hose. Pic is before alternator update and A/C install, although it looks very similar currently.
 

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Discussion Starter #16
Got pics of your engine bay? Whether it’s good or bad I just want to get ideas of how others have their conversions setup. Thanks!
Mine is definitely a driver. I wanted as close as possible to the fox setup for simplicity of repairs and surprise factor. No attempt was made to hide the "busy" starter solenoid, just like the fox underhood. ECM is under carpet on trans hump. The strut tower brace had to be clearanced for the intake elbow and keyholed for the EGR vacuum hose. Pic is before alternator update and A/C install, although it looks very similar currently.
This would work for me too! Where did you mount all the relays and fuses?
 

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I mounted the ECU in the passenger side kick panel area (made a box to fit it), but it could fit behind the glove box area. I mounted all of the relays in the glove box so they are easily accessible and placed the OBD1 connector near the pass kickpanel at the bottom of the dash. I also used the Ron Francis wiring. A picture of the engine compartment is on my website below. Hope this helps...
 

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Attached is a photo of the 5.0 install in our 66 Coupe along with a shot of the car. Of course, ours is a Restomod rather than a restoration. Clean wiring is one sign of a well built car (hot rod) but it takes lots of planning and patience. Most of our major wiring components, including the battery, are located in the trunk or under the dash. Of course this remark applies to modified Mustangs as I've gone the restoration route as well. In that case, the best look is closely duplicated factory wiring.
 

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