Gen 3 Coyote Wiring Questions - please confirm my logic here...

[mmklaxer]

I'm slowly stepping into the wiring phase of this journey, and admittedly I'm not super comfortable with this step of the process for 3 reasons:
1. I'm not super familiar with DC systems
2. Without unwrapping all the harnesses, I'm depending on the schematics
3. on top of the two above, the Coyote instructions are a merger of the RF instructions and the Coyote instructions.

I'm going to follow the instructions as close to the prescribed method as possible, but I do have some changes I'd like to make. I'd appreciate a review of the below actions to makes sure I'm not screwing something up royally.

Before I get into the below, I will mention that I have a master disconnect incorporated into the build.

RF Chassis Harness Starter leg. Instructions: 3 red wires attach to the starter solenoid, and the blue wire is cut out/not used for coyote.
My Plan: run switched power from the master cutoff to a bus bar and attach the 3 starter wires to it. That should eliminate an entire leg of the harness. Then power runs from the master cutoff to the starter (the EdwardB method...hahaha).

RF Chassis Harness Alternator leg. Instructions: Run the red power wire to the alternator, but I don't see instructions for the brown wire. In the Coyote instructions, the coyote harness alternator plug attaches to the alternator, meaning that PCM controls the alternator.
My plan: run power from the bus bar to the alternator. That should eliminate an even larger leg of the RF chassis harness.

RF Hot Rod leg. Instructions: tie wrap it to the main harness.
My plan: cut it out and tape the ends to ensure no shorts. This should free up some space in the footbox

Seat Heaters: Plan to use the heater power wire in the RF Chassis harness to power the cobraheat seat heaters. Just connect the red wires from the cobraheat to the heat wire from the chassis harness, then ground the black wires.

USB Charger: As I will not have a radio, I planned to use the radio power wire which is fuzed already to run power to a USB plug, something like this: https://powerwerx.com/backlit-blue-panel-mount-usb?gclid=CjwKCAiA2L-dBhACEiwAu8Q9YC89qJn8KP9x84vt2uHLxvu7WTXwcGKBcHgfq GeoRMuJLOcbw-I4QBoCX3wQAvD_BwE
Then run a wire from the negative terminal of the USB to ground. I would NOT need the radio memory wire.

Fuel Pump control: The Coyote instructions are clear that the green wire in the controls pack controls the fuel pump, so I cut the short orange wire in the panel. The green wire connector also has 2 short wires labeled "SMK and Toggle" I see no reference as to what to do to those anywhere in the instructions. Unnecessary for these builds?

I'm sure I'll have more questions, but these will help get going for sure! Thanks in advance!

Happy New Year!!

[mladen]

I'm not using a Coyote engine so can't help there, but for the other stuff:

Most people reuse the wiper/heater/radio leads as you mentioned. I ended up installing an additional fuse box and running from there. My concern was that heaters say they require you handle a 10amp draw, but the wires they come with are quite thin, so you're probably more than fine with using the heater wire. Similar for USB, you can definitely use the wiper or radio. Do note that one of the radio wires comes off the Battery and always has power even if you don't turn the ignition to accessory.

For the alternator, again, different engine, but mine is a single wire alternator, so I just removed the brown wire from the harness.

Hot rod branch, it really doesn't take much space so I just left it in, but yeah, you could cut it off as you said

[mmklaxer]

Thanks for the heads up on the radio wire being hot all the time. I imagine it's the radio memory wire to maintain settings. I'll see if I can't figure it out on the schematic. I'd prefer the USB charger to not constantly drain, as the USB port I like has a backlit feature that would always pull on the battery if always hot.

[i.e.427]

Thanks for the heads up on the radio wire being hot all the time. I imagine it's the radio memory wire to maintain settings.

There are two wires for the radio. They are both marked on the ends of the wires. The red one is radio memory and the other is switched power for the radio. I believe it is a brown wire (best I remember) The Coyote requires the red heavy gauge wire from the RF chassis harness marked "alternator" connect to the main alternator stud. The Coyote wiring engine harness has a plug that connects to the control side of the alternator and is controlled by the Ford Control Pack. We have a number of wiring videos that are specific to the Coyote in particular. Many of the items on you list above are covered.

https://www.youtube.com/@i.e.427garage9/videos

[edwardb]

Was doing OK with all your points until the last one. "The green wire connector also has 2 short wires labeled "SMK and Toggle" I see no reference as to what to do to those anywhere in the instructions. Unnecessary for these builds?" Do you mean the light blue "SMR" and light green "Trigger" wires in the Coyote 6-way I-P pigtail connector? If so, those are absolutely required and the engine will not start or run without them connected. SMR goes to the blue start wire. Puts +12V on the wire when the key is in the start position and triggers the ECM to start the engine. Trigger goes to a +12V source that is always on when the key is on. Most use the orange EFI wire. Although I've also used the choke wire. Tells the system to turn on and stay on as long as the key is on. Both of these are in the Ford and Factory Five instructions. If not the ones you're asking about, then more details please.

[mmklaxer]

There are two wires for the radio. They are both marked on the ends of the wires. The red one is radio memory and the other is switched power for the radio. I believe it is a brown wire (best I remember) The Coyote requires the red heavy gauge wire from the RF chassis harness marked "alternator" connect to the main alternator stud. The Coyote wiring engine harness has a plug that connects to the control side of the alternator and is controlled by the Ford Control Pack. We have a number of wiring videos that are specific to the Coyote in particular. Many of the items on you list above are covered.

https://www.youtube.com/@i.e.427garage9/videos

Thanks for the link. Your videos are super helpful for the novices out there

[mmklaxer]

Was doing OK with all your points until the last one. "The green wire connector also has 2 short wires labeled "SMK and Toggle" I see no reference as to what to do to those anywhere in the instructions. Unnecessary for these builds?" Do you mean the light blue "SMR" and light green "Trigger" wires in the Coyote 6-way I-P pigtail connector? If so, those are absolutely required and the engine will not start or run without them connected. SMR goes to the blue start wire. Puts +12V on the wire when the key is in the start position and triggers the ECM to start the engine. Trigger goes to a +12V source that is always on when the key is on. Most use the orange EFI wire. Although I've also used the choke wire. Tells the system to turn on and stay on as long as the key is on. Both of these are in the Ford and Factory Five instructions. If not the ones you're asking about, then more details please.

You are largely correct. Went back out to the garage and saw the "SMR" marking vs the "SMK" i thought i saw on the light blue wire. The green one definitely says Toggle vs Trigger.
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With your description I found the instructions in the manual. Where I was thrown off was in the manual on page 86 it tells you to install the 6-way pigtail connector. Then 16 pages later it tells you to install the SMR and TRIGGER wires to the EFI wires. When I got there, I was looking in the ron francis harnesses for the SMR and Trigger, as they had the RF -looking white labels, and mine does not. Bonehead move on my part. Having said that, I'm not a technical writer by any means and give FF all the credit in the world for a fairly comprehensive manual, given the variability in our builds. For how my mind works, it would have made more sense to check off the installation of all 3 wires at the same time in the manual, under a heading of "6-way I-P Pigtail" that reads "hook this thing up, then this is what you do with the 3 wires. Not complaining, just a different way of thinking.
177539

All that being said, does the rest of my logic compute for the other wire routing plans I laid out?

[mmklaxer]

Quick update. Stripped the loom off the starter and alternator legs. Fundamentally it looks to be set up stock configuration to run battery power to starter, then one of the red wires runs power to the alternator. In my set up, it’s battery power to master cut off, from their power to the starter and to the bus bar, and from the bud bar to the alternator. Should still supply power as intended.

[edwardb]

You are largely correct. Went back out to the garage and saw the "SMR" marking vs the "SMK" i thought i saw on the light blue wire. The green one definitely says Toggle vs Trigger.
177538
With your description I found the instructions in the manual. Where I was thrown off was in the manual on page 86 it tells you to install the 6-way pigtail connector. Then 16 pages later it tells you to install the SMR and TRIGGER wires to the EFI wires. When I got there, I was looking in the ron francis harnesses for the SMR and Trigger, as they had the RF -looking white labels, and mine does not. Bonehead move on my part. Having said that, I'm not a technical writer by any means and give FF all the credit in the world for a fairly comprehensive manual, given the variability in our builds. For how my mind works, it would have made more sense to check off the installation of all 3 wires at the same time in the manual, under a heading of "6-way I-P Pigtail" that reads "hook this thing up, then this is what you do with the 3 wires. Not complaining, just a different way of thinking.
177539

All that being said, does the rest of my logic compute for the other wire routing plans I laid out?

What I said was 100% correct. Not just largely... :rolleyes: Have done it several times. Clearly Ford has made minor changes. The latest documentation on their website calls these two wires "Starter Motor Request (SMR)" and "Ignition Relay Trigger." Earlier versions of the Ford harness had paper labels like you pictured and illustrated in the FF instructions. Looks like they've changed to direct wire marking and changed the one to "Toggle." Confusing I guess but maybe not if you focus on the purpose and how they work. You won't find matching labels or descriptions on the Ron Francis wires. Only what's shown on their schematic. Their harness isn't just for a Coyote. As you said in your first post, wiring this thing takes both the FF instructions and the Ford instructions. To be honest, I found the Ford instructions to more helpful. I did my Gen 3 in the Coupe before FF released instructions. No big deal. At the end of the day, the engine won't start or run without these two wires properly connected. Hopefully you have what you need to complete.

As or the rest, I said in my first post it looked OK.

[mmklaxer]

Thanks so much Paul!

[toadster]

RF Hot Rod leg. Instructions: tie wrap it to the main harness.
My plan: cut it out and tape the ends to ensure no shorts. This should free up some space in the footbox


you're right where I was at a few weeks ago, everything Paul mentioned is spot on, Ford has relabeled those lines, but they're still similar in name

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as for the Hot Rod leg (above) - I don't believe you cannot just cut it and tape it - there is some continuity required.
I know some have done it. I opted to ziptie it in the footbox and forget about it :)

[mladen]

as for the Hot Rod leg (above) - I don't believe you cannot just cut it and tape it - there is some continuity required.

Looking at the diagram (revision W) looks like all the hot rod wires are connected in parallel with wires elsewhere, so they should be fine to just cut. Unless I'm reading something wrong.

[toadster]

here's where I asked the same question, it seems that there's a 2 into 1 wire setup that needs to be kept together, but otherwise can be cut

https://thefactoryfiveforum.com/showthread.php?40471-for-the-Ron-Francis-Wiring-Harness-do-you-remove-the-3-non-used-plugs

[edwardb]

Looking at the diagram (revision W) looks like all the hot rod wires are connected in parallel with wires elsewhere, so they should be fine to just cut. Unless I'm reading something wrong.


here's where I asked the same question, it seems that there's a 2 into 1 wire setup that needs to be kept together, but otherwise can be cut

https://thefactoryfiveforum.com/showthread.php?40471-for-the-Ron-Francis-Wiring-Harness-do-you-remove-the-3-non-used-plugs

It's not that they need to be kept together. It's that you need to make sure to cut off the right one, e.g. the wire to the hot rod connector not the other one. That is if you go so deep into the harness that you're tracing the hot rod wires all the way back to where they originate, which in some cases is at connectors.

The answer to the larger question is the hot rod connector can be safely removed. All the wires are parallel connections from the "regular" harness connections. Just have to be careful if you don't unwrap the harness and take them back to their source (not required or recommended unless you feel up to it) the wires are still live. So make the cuts different lengths and insulate the ends. Mentioned in the linked thread. I've removed the hot rod connector from all my builds without issue. Except the truck build where it's actually used.