Gen3 Coyote Starter wiring

[Junbug]

So these 4 wires all feed down into the starter leg of the harness.
https://thefactoryfiveforum.com/attachment.php?attachmentid=188369&d=1691298248
What I understand of the red ones: one goes to the ignition, one goes to the alternator and the last goes to the fuse block. Do all three stack and connect to the same pole on the starter?
Likewise, the blue cable, I don't believe is necessary with a Coyote and can be removed. That said, since the Coyote has its separate clutch safety switch on the main Coyote harness, it isn't necessary. Curious if anything needs to run to the ignition switch or does the Coyote computer know from its own sensor?

Please correct me if I'm misguided or wrong anywhere!
Thanks,
-Bryan

[mmklaxer]

Ok, so this is where i believe you're starting to deviate from the manual. IIRC, you have a master disconnect switch, and we've been talking about bus bars. In that case what many have done is run a larger cable (i ran a #4) from the starter to the switched side of the master disconnect. That makes it just 1 cable. on the starter. Then power runs from the disconnect to the bus bar. The bus bar distributes the power to whatever you want. With this, you can eliminate the starter run all together, as you are correct about the blue starter wire in that leg of the chassis harness. its functionality is replaced by the controls pack starter wire.

When you strip the starter leg of the harness, you'll find the alternator power wire just runs up the starter leg and down the alternator leg. It doens't run through anything else, splice with anything etc - just transporting electrons from A to B. That wire I repurposed through the bus bar to run to the alternator.

[edwardb]

mmlaxer makes some correct points. The Ron Francis harness schematic says "starter solenoid" for all those wires. But IMO that's reminiscent of the days when there was a firewall solenoid. With the current generation of starters (for a long time now) the starters have an integral solenoid so there's no need for a firewall solenoid or to drag the wires down to the starter solenoid. Some still use a firewall solenoid for various reasons. But not required in my experience. None of my builds have had one. The wires do need to go to battery voltage or through a disconnect if you're using one. But that can be from a firewall switch, binding post, bus strip, whatever. The only thing you need to the starter is +12V from the battery to the large post. This is the same for all builds. Not just for a Coyote. The only difference is the Coyote control pack has it's own starter wire which goes to the small post. You won't use the Ron Francis blue wire which goes through the Ron Francis clutch safety switch. Also not used with the Coyote since a clutch switch is part of the control pack. You can either tie the blue wire out of the way or remove it completely. There's another blue start wire off the ignition switch that does need to go directly to the Coyote control pack Starter Motor Request (SMR) wire.

One last comment. The Factory Five instructions are (again IMO) a little confusing on the blue start wire. Especially if you're not 100% confident doing the wiring. They describe using the Coyote start wire "if you want the PCM to control the starter." They also say you can use the Ron Francis blue start wire if you want and not have PCM control. I have no idea why you want to do the latter. I haven't and haven't seen any builds that did.

[Dgc333]

FYI, all three of those red wires in the picture ultimately need to connect to the positive side of the battery whether you connect all of them with the battery cable to the large post on the starter or via a buss bar mounted else where.

One of them goes to the fuse panel for the items that power on regardless of the ignition switch like head lights and emergency flashers. One goes to the ignition switch for those items that are turned on and off with the key. The third one goes to the alternator output terminal so the alternator can charge the battery.

The Blue wire would connect to the small terminal on the starter and would activate the solenoid to spin the starter. It goes through the clutch safety switch back to the start terminal on the ignition switch. This would not be used if you have an EFI system that controls the starter.

FWIW, I have a Hemi in my 33 and a factory based ECU. The ECU controls the starter so I don't use the blue wire. The ECU also controls the fuel pump so the relay, fuse and inertia switch in the RF harness for the fuel pump are not used and there is no connection made to the ignition switch from this wiring in the RF harness. The Hemi harness has its own fuse block and relays for all the engine functions.

[Junbug]

mmlaxer makes some correct points. The Ron Francis harness schematic says "starter solenoid" for all those wires. But IMO that's reminiscent of the days when there was a firewall solenoid. With the current generation of starters (for a long time now) the starters have an integral solenoid so there's no need for a firewall solenoid or to drag the wires down to the starter solenoid. Some still use a firewall solenoid for various reasons. But not required in my experience. None of my builds have had one. The wires do need to go to battery voltage or through a disconnect if you're using one. But that can be from a firewall switch, binding post, bus strip, whatever. The only thing you need to the starter is +12V from the battery to the large post. This is the same for all builds. Not just for a Coyote. The only difference is the Coyote control pack has it's own starter wire which goes to the small post. You won't use the Ron Francis blue wire which goes through the Ron Francis clutch safety switch. Also not used with the Coyote since a clutch switch is part of the control pack. You can either tie the blue wire out of the way or remove it completely. There's another blue start wire off the ignition switch that does need to go directly to the Coyote control pack Starter Motor Request (SMR) wire.

One last comment. The Factory Five instructions are (again IMO) a little confusing on the blue start wire. Especially if you're not 100% confident doing the wiring. They describe using the Coyote start wire "if you want the PCM to control the starter." They also say you can use the Ron Francis blue start wire if you want and not have PCM control. I have no idea why you want to do the latter. I haven't and haven't seen any builds that did.

Thanks Paul. That all makes sense.
Two questions,
1. Where in the Coyote controls pack is the SMR wire?
2. Can I remove both of the light blue wires coming from the FFR harness clutch safety switch? It appears neither are needed? I’m tracking I need the thinner blue wire from the ignition to the SMR mentioned in #1 above.
Thanks,
-Bryan

[Junbug]

Ok, so this is where i believe you're starting to deviate from the manual. IIRC, you have a master disconnect switch, and we've been talking about bus bars. In that case what many have done is run a larger cable (i ran a #4) from the starter to the switched side of the master disconnect. That makes it just 1 cable. on the starter. Then power runs from the disconnect to the bus bar. The bus bar distributes the power to whatever you want. With this, you can eliminate the starter run all together, as you are correct about the blue starter wire in that leg of the chassis harness. its functionality is replaced by the controls pack starter wire.

When you strip the starter leg of the harness, you'll find the alternator power wire just runs up the starter leg and down the alternator leg. It doens't run through anything else, splice with anything etc - just transporting electrons from A to B. That wire I repurposed through the bus bar to run to the alternator.

Thanks Mike! I guess I drilled a hole in my firewall for no reason :) I’ll take a look at pulling the alternator/starter harness back through the dash and re-working the alternator wire.
-Bryan

[i.e.427]

Go to the 10 minute mark in the video. We talk about the discussion we had with Ford Racing and their suggestions for landing those wires.

Frank


https://www.youtube.com/watch?v=oVQsgimPvpw&t=1114s

[edwardb]

Thanks Paul. That all makes sense.
Two questions,
1. Where in the Coyote controls pack is the SMR wire?
2. Can I remove both of the light blue wires coming from the FFR harness clutch safety switch? It appears neither are needed? I’m tracking I need the thinner blue wire from the ignition to the SMR mentioned in #1 above.
Thanks,
-Bryan

1. It's in the Coyote "pigtail." Color is light blue. Along with the Ignition Relay Trigger (light green) which has to be attached to an ignition switched circuit. Many use the RF harness EFI wire. I used that on my Roadster. For my Coupe I used the choke wire. Either works as long as it has +12V at all times that the ignition switch is on. The Ford Performance instructions for the control pack shows the harness and all the connections very clearly.

2. If you look at the Ron Francis harness diagram in the installation instructions, you'll see two blue wires coming off the ignition switch "start" lug. One can be traced over to the clutch safety switch and then out to the starter solenoid. That's the wire you don't need. As I mentioned before, can be tied out of the way or removed. The other blue wire off the ignition switch marked EFI CRANK WIRE should go to the SMR wire in the Coyote harness pigtail.