Coyote/Chassis Wiring Question

[mlewis]

Hi All,

Working on my electrical (Coyote/FFR Chassis wiring/FFR GPS gauge set). Not my strong suit.

All seems to be going well. Trying to sort out some of the redundant wires and other connections.

Based on my configuration, I assume I don't need the following:

1) green & grey wire labeled SPEED SENSOR
2) brown wire labeled ELECTIRC CHOKE
3) green wire labeled FAN THERMO
4) brown wire labeled ALTENATOR ING (I know some guys wire this to a charge light circuit - but I'm not planning to do that)

I am assuming I can cut/remove the above ?

I'm thinking of re-purposing the following:

5) brown wire labeled HEATER - this appears to be on a 20 amp circuit. I would like to use this to power my heated seats, any concerns ?
6) brown wire labeled RADIO POWERE - not planning a radio, I would like to use this to power a couple USB charge sockets, any concerns ?

7) red wire (from the coyote harness) labeled HAAT - since this has power "at all times", I would like to use this to power the speedo/GPS and clock (ideas from Paul), any concerns ?

8) if I do the above on items 7, I assume I can use the red wire labeled RADIO MEMORY for something that needs power all the time (but disconnects by the master power switch).

Greatly appreciate any/all feedback on the above items.

I will have a couple more questions on connecting to the oil & temp sending units and on connecting to the Russ Thompson turn signal.

Thanks again !

[Al_C]

Mostly, it sounds reasonable. I would not cut any of them, because you will find a use for them (as you have in many cases). Your green and grey speed sensor wires would ordinarily be connected to the transmission sender, but if you have the GPS speedo, I guess you don't need them. (I used them...)

[edwardb]

All OK. Just a couple minor comments.

#2: That 10 amp choke wire is a nice ignition controlled circuit with nothing else on it. On my Couple build, I ended up using that wire for the Coyote ignition relay trigger (light green) instead of the more commonly used EFI/Coil wire. The EFI/Coil wire is a dedicated 15 amp circuit, and the Coyote doesn't need the current. Just the 12 volt signal. I used the EFI/Coil circuit in my Coupe build for the USB ports.

#6: That 10 amp circuit is also shared with the gauge power feed. Probably not a problem, but you could get a dedicated circuit for your USB ports by using either the choke or EFI/Coil circuits as note in the previous point. Only caveat is the Gauge/Radio circuit is on the accessory bus, so available power with the key in the accessory position. The other ones are on the ignition side. If that matters.

#7: Works perfectly as you described. Just make sure there's a fuse for that circuit in the PDB. Mine didn't have one. Unfortunately, Ford deleted the HAAT wires on the Gen 3 Coyote.

[mlewis]

Thanks for the responses.

#2: That 10 amp choke wire is a nice ignition controlled circuit with nothing else on it. On my Couple build, I ended up using that wire for the Coyote ignition relay trigger (light green) instead of the more commonly used EFI/Coil wire. The EFI/Coil wire is a dedicated 15 amp circuit, and the Coyote doesn't need the current. Just the 12 volt signal. I used the EFI/Coil circuit in my Coupe build for the USB ports.

I see your point, but I already follow the guides of the Coyote Fitment instructions and connected these to the Coyote SMR/TRIGGER.

#6: That 10 amp circuit is also shared with the gauge power feed. Probably not a problem, but you could get a dedicated circuit for your USB ports by using either the choke or EFI/Coil circuits as note in the previous point. Only caveat is the Gauge/Radio circuit is on the accessory bus, so available power with the key in the accessory position. The other ones are on the ignition side. If that matters.

Another good point. Given my above response, what about the brown wire labeled ELECTIRC CHOKE (10 amp on the ignition feed side) to power the USB ports ? Could also use the RADIO MEMORY line (not planning to install a radio)?

Works perfectly as you described. Just make sure there's a fuse for that circuit in the PDB. Mine didn't have one. Unfortunately, Ford deleted the HAAT wires on the Gen 3 Coyote.

. Bummer on the Gen3. I checked the Ford instruction and PDB, looks like it controlled by a 10a fuse.

[edwardb]

Given my above response, what about the brown wire labeled ELECTIRC CHOKE (10 amp on the ignition feed side) to power the USB ports ? Could also use the RADIO MEMORY line (not planning to install a radio)?

Either would work. Main difference would be choke is an ignition circuit and is switched. Radio memory is a battery circuit and always on. If you left something plugged into a USB port on a battery circuit, by accident or too long, could discharge your battery. But maybe you want the ports to always be powered. Your choice.

[bluse]

Regarding item #5 in the original post using the 20a heater circuit for heated seats. Is it common practice to connect both seats to (1) 20a circuit? The Warm Seat instructions show connecting each seat to a 10a fused circuit. The seats come with an inline 10a fuse so is it acceptable to connect both seats to the brown 20a heater wire? Should the inline fuses still be used?
Thanks

[edwardb]

Regarding item #5 in the original post using the 20a heater circuit for heated seats. Is it common practice to connect both seats to (1) 20a circuit? The Warm Seat instructions show connecting each seat to a 10a fused circuit. The seats come with an inline 10a fuse so is it acceptable to connect both seats to the brown 20a heater wire? Should the inline fuses still be used?
Thanks

The 20 amp heater circuit works perfectly for the two warm seat heaters. I don't remember the exact number, but I measured the current draw with both on high it and it was under the 20 amps. In actual use with several builds and that setup, never blew a fuse. I removed the in-line fuses on the installations I've done since the circuit is protected by the fuse in the RF panel. In theory they don't hurt anything. But just adds another failure point that may not be easily accessible.

[Jryasko]

Just a comment on the heater wire for seat heaters. I to used the heater wire to power the seat heaters, but with a little twist. I added a 4 circuit aux fuse panel to the right side of the glove box ( vinyl dash) ran the heater wire to that to power it and with that you have a nice place to connect the wires as well as a fuse for each side of the seat heaters there as well. Drilled and tapped a hole in the 2 in tube next to the aux panel for the grounds and everything is good. Aux panel was a Blue Seas Marine piece, it has a cover to protect the terminals as well.

[nuhale]

Regarding item #5 in the original post using the 20a heater circuit for heated seats. Is it common practice to connect both seats to (1) 20a circuit? The Warm Seat instructions show connecting each seat to a 10a fused circuit. The seats come with an inline 10a fuse so is it acceptable to connect both seats to the brown 20a heater wire? Should the inline fuses still be used?
Thanks

I used the radio line with a 20a fuse. I had them on for a couple hours at a time and have not had an issue/no blown fuses. Like Paul I measured the draw in installation and tested them to make sure no issue. I did not use the inline fuses.

[edwardb]

I used the radio line with a 20a fuse. I had them on for a couple hours at a time and have not had an issue/no blown fuses. Like Paul I measured the draw in installation and tested them to make sure no issue. I did not use the inline fuses.

Potentially risky practice there. The radio circuit only has a 10 amp fuse. Not usually a good idea to take out a fuse and replace with a higher rated one. Often the wire in the circuit is sized for the planned current. If you confirmed the radio circuit has the same gauge wire as the heater circuit, should be OK. But something to check if you haven't.

[nuhale]

Checked with a meter with both heaters on high and was around a 10amp draw. The radio wire is 16ga and is acceptable at this length.

[rich grsc]

Checked with a meter with both heaters on high and was around a 10amp draw. The radio wire is 16ga and is acceptable at this length.

Even though the load is 10amp, you have a 20 amp fuse on a 10 amp wire. That is the problem. Sure the heaters won't over heat the wire, but if there is a short or bare wire, the wire will be damaged before the fuse blows. The fuses are sized to the wire, not the load. Better safe than sorry

[D Stand]

Even though the load is 10amp, you have a 20 amp fuse on a 10 amp wire. That is the problem. Sure the heaters won't over heat the wire, but if there is a short or bare wire, the wire will be damaged before the fuse blows. The fuses are sized to the wire, not the load. Better safe than sorry

16 gauge is good for 20 amps if it is less than 2.9ft. It is only rated for 10 amps if it is 5.8ft long. This is probably why it was fused at 10 amps. If the heaters do not draw more than 10 amps then simply replace the fuse back to the 10 amp fuse and all will be good. I personally would go with the advise of others and utilize one of the other 20 amp rated circuits for the seats..

[Redlinejoev]

The 20 amp heater circuit works perfectly for the two warm seat heaters. I don't remember the exact number, but I measured the current draw with both on high it and it was under the 20 amps. In actual use with several builds and that setup, never blew a fuse. I removed the in-line fuses on the installations I've done since the circuit is protected by the fuse in the RF panel. In theory they don't hurt anything. But just adds another failure point that may not be easily accessible.

Very interesting thread but I have a question regarding the seat heaters being used with the heater as well. Can the heater AND the seat warmers be wired in the same circuit?

[edwardb]

Very interesting thread but I have a question regarding the seat heaters being used with the heater as well. Can the heater AND the seat warmers be wired in the same circuit?

Hard to answer without definitive current numbers. But I wouldn't recommend it. If you have the space heater, put it on the 20 amp heater circuit as designed and use a different circuit for the seat heaters.

[Redlinejoev]

Hard to answer without definitive current numbers. But I wouldn't recommend it. If you have the space heater, put it on the 20 amp heater circuit as designed and use a different circuit for the seat heaters.

Thank you Paul. I don't have much experience with the wiring aspect of the build, your answer confirms what I expected but I was hopeful. I'll have to find another circuit to use. Thanks again for sharing your expertise with the rest of us.