Wiring Clarification and Qs

[Mat1asBEV&ICE]

Hola. I’m knee deep in wiring and I’m having some confusion and uncertainty even after reading build threads. Unfortunately, I’m not one of those people that deals well with uncertainty.

Using Gen 3 Coyote, GPS gauges.

1. RF front harness, I can remove the cooling fan wires. Can I also remove that ground cable? Seems like it.
2. Regarding the “fuel pump wire from the EFI harness” that I need to connect to the orange fuel pump relay control wire. It’s the very long green wire that connects to the “inline to I/P pigtail”, correct? It doesn't have a label/marking. Just use a red butt connector?
3. SMR wire in pigtail connects to “EFI crank” wire?
4. The green wire in pigtail labeled “toggle” connects to the orange “coil or EFI” wire?
5. Do I need the other three wires (included with the two wires in bullets 3 and 4) in the “coil/EFI crank” bundle for anything?
6. RF starter solenoid wires: I am having difficulty seeing how people get rid of all three red wires from coming through the firewall. I know a bus bar is involved. Then I get a little bit lost. I am hoping to mount the PDB on the firewall and mega fuse below it as others have done along with a cutoff switch.
7. Any tricks/tips for mounting the mega fuse below the firewall?

Thank you!

[BrewCityCobra]

Ahh, wiring. Always fun.

A few quick comments to get you started:

1) I also considered pulling the ground wire from the front harness but in the end was told (and I cannot remember where) that using the ground wire is preferred to just running the headlights/parking lights/etc. through the chassis. So in the end I ended up leaving the ground wire in and wired the headlights/etc. accordingly. I can't guarantee that there is a real difference but I just felt better sticking with what was in the harness and the advice I got on the board to that point.

6) I included a schematic on how I did my "battery harness" in my build: https://thefactoryfiveforum.com/show...l=1#post482433 It shows where I positioned my fuses(I ended up using a 200 Amp re-settable breaker from Del City) and what wire sizes and circuits I ran to feed the bus bar. That bus bar (on the right side of the schematic) is ultimately where I attached all the "red" wires from the RF harness to power the harness. If you continue through my build you will see some other schematics and photos that may be of help in the "battery harness" area and otherwise.

7) Depends what you are ultimately running and how you want to incorporate it into the circuit. But if you decide to go with a circuit similar to mine (e.g., between the master cutoff and the bus-bar), I found putting it up near the passenger-side F-panel made for easy packaging.

20220212_161800.jpg

[Mat1asBEV&ICE]

Thank you, BrewCity. The schematic really helps. What is "to LT blu-start sol"?

I will have to make some changes as I have a Coyote.

[Mat1asBEV&ICE]

Okay, I think I have figured it out. Is the wiring schematic below accurate? Please don't assume I know anything. Point out any FYIs and "don't forget to's". Thank you!
Screenshot 2024-04-04 at 11.40.24 AM.png

[BrewCityCobra]

Sorry for the delay. The LT Blu-start sol is the solonoid starter wire that triggers the starter itself.

[BrewCityCobra]

Okay, I think I have figured it out. Is the wiring schematic below accurate? Please don't assume I know anything. Point out any FYIs and "don't forget to's". Thank you!
Screenshot 2024-04-04 at 11.40.24 AM.png

So a few quick comments (but give me some rope because I didn't do a Coyote build so I'm not really sure how the PDB is supposed to be wired). Also, it is worth noting that some of my comments are dependent upon how you want to use your cutoff switch. If you just want the cutoff to simply isolate your battery so it won't be run down in the winter that is one way to use it, others use it as a safety cutoff where if you turn it off everything loses power and the engine must turn off, and still others (like myself) do both. Either is fine, just wanted to point that out because it will influence how you wire things.

With that said, how you have this laid out the PDB will not get cutoff in an emergency should you flip the cutoff switch. It will also continue to draw current from the battery if you have the system "sitting" for long periods with the cutoff open. Now I'm not sure if the wiring rules for the PDB require that, but just wanted to point it out. Like I said above, when I wired mine I wanted to make sure that everything would get isolated from the battery and alternator so the engine had to shutoff. If that is what you want, you can easily fix that by just wiring the PDB off the top terminal instead of the bottom on your schematic.

Second, you have the alternator going directly back to your harness. It is my understanding (from advice from this board) that such a layout can be problematic on two fronts. First, an alternator overrun can send a surge of power through your harness, so many (like myself) put a megafuse or circuit breaker on that wire. Not required, but extra insurance. The photo of the circuit breaker I included in my first post shows the circuit breaker I incorporated for that reason (it is the square element in my schematic). Second, the alternator will continue to provide power to your harness even if you want to shut everything down (e.g., it does not run through the cutoff switch). So that is something that, again, you don't need to do but if you are looking for total electrical isolation, you would want to run that through the cutoff switch as well. This, too, can be easily remedied by running the alternator wire to the bottom post of your cutoff switch.

The only wire I can't really comment on is the wire running from the PDB to the starter, not sure how that one works (although I'm guessing it is the solonoid trigger in which case it looks correct).

[Mat1asBEV&ICE]

Hi Brew. Thank you for your input!

The PDB does require power all the time per the manual instructions. Constant PDB power is how many Coyote builders have done it as well. My purpose is to use the cutoff to prevent running down the battery during winter. Again, I believe this is how others do it as well.

Thank you for your point regarding the wire from the RF to the alternator. I will have to dig into that. Easy enough to add a fuse. Perhaps I'll just run from the battery directly to the alternator.

[BrewCityCobra]

Good to know, I wondered if that was the case when looking at your schematic.


Yeah, I unfortunately can't remember where I found all the information on the alternator front. That's effectively what I did (with some wires in-between)

[Mat1asBEV&ICE]

Well, I'm going to go with this unless someone with a Coyote tells me otherwise. All the other RF and Ford Performance harnesses are self explanatory so I didn't include them. This way I don't need any RF harness wires coming through the firewall.