MAIN RF HARNESS – new/modified circuits

NOTES:

1. RED-COURTESY LT (15A fuse, BATT FED) – route to courtesy light relay coil (+) pin 86 and relay device power pin 30 behind dash; shared 15A fuse w/ RED-RADIO MEMORY
• Each ¾” LED draws 30mA (or .030A), so 0.36W total per LED. 10x.030A = 0.3A total for all 10 lights (very little)
2. GRY-TO HDLT SW (loose wire) – route to courtesy light relay coil (-) pin 85 behind dash (tied to chassis ground on the headlight switch)
3. RED-RADIO MEMORY (15A fuse, BATT FED) – same circuit as RED-COURTESY LT; Use this for the reverse light
4. TAN-ELECTRIC CHOKE (10A fuse, IGN FED) – use for Coyote light green Ignition Relay Trigger from Coyote pigtail
5. ORG-EFI OR COIL (15A fuse, IGN FED)
• use for footbox blowers (they each use max 2.5A, so 5A total on the circuit if both are in use)
• Split this feed to two separate relays, and OK to use it for the relay coil positive and device power input, then use each blower switch on the dash to negative trigger the relay
• Want IGN feed because don’t want to accidentally leave on and drain battery
• Also use for Maradyne fan PWM controller (low power draw)
• Split off a wire to the reverse lockout module (requires +12V IGN) – should work OK (rarely used)
6. DK BLU-COOLING FAN (30A fuse, BATT FED) – since I’m controlling the cooling fan with the Coyote ECU and Maradyne controller, I disconnected this wire in the front harness (clipped blue wire at fuse panel, heat shrink the ends) – I used the cooling fan blue wire going to front harness for the footbox blower feeds; I extended this blue wire back into the dash….for the blowers, use the ORG-EFI OR COIL wire (15A fuse, IGN FED) as a +12V feed going to two separate relays (one for each blower), then the output of the relays goes to each blower via the blue wire. The 30A fuse (BATT FEED) & Cooling Fan relay are currently not in use and can be repurposed as needed.
7. DK GRN-FAN THERMAL SWITCH – this branches to the FRONT HARNESS and SENDING UNIT HARNESS – should be OK to remove from sending unit harness or just cap the end and leave it. For the one going through FRONT harness, I’m using it to power the courtesy light in the front DS F-panel, so cut the wire on the main harness side, and attach it to the RED-COURTESY LT behind the dash with the other courtesy light connections 🡪 maybe trace this back to where it splits, and just connect it to the RED-COURTESY LT from there? DONE.
8. BRN-RADIO POWER (10A fused, ACC FED) –
• use this for the AUX USB ports, both under the dash and on trans tunnel. This same circuit feeds the gauges on the dash, so look at total power load and consider using a 15A fuse if needed. May be OK w/ 10A fuse
9. PURP-WIPER (10A fused, ACC FED)
• use this for the actual wiper power
10. BRN-HEATER (20A fused, ACC FED) – use this for actual heater power
11. *NEW CIRCUIT for seat heater (15A fuse, IGN FEED)* NEW WHITE WIRE IN RF MAIN HARNESS - was originally going to splice off the ORG-IGNITION wire coming from the ignition and bring that to the new fuse block, but instead I re-used the 15A IGN FEED for the fuel pump circuit. For the fuel pump, I decided to use the green FUEL PUMP RELAY OUT from the Coyote pigtail to trigger AND power the fuel pump relay (in RF fuse panel), instead of this circuit. So I repurposed this circuit for the seat heaters white wire going behind dash 🡪 branch this into both seat heater power wires. To do this, I reversed the current direction through the 15A fuse. Originally it got battery power, but I changed it so it gets IGN power instead.

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LIST OF MODIFICATIONS:

Fuel Pump Circuit

NOTES:

• You have 2 ways to do this:
• OPTION 1 – use the green FUEL PUMP RELAY OUT wire on the Coyote pigtail to trigger the RF fuel pump relay (positive trigger) – this is how the FFR Coyote Fitment instructions say to do it. In this setup, the Coyote ECU is only triggering the fuel pump relay, but the actual power for the fuel pump comes from the RF harness. The downside is that now there are 2 fuses and 2 relays in this fuel pump circuit, one in the RF panel and one in the Coyote PDB.
• OPTION 2 (preferred per this post) – I USED THIS METHOD - use the green FUEL PUMP RELAY OUT wire from the Coyote pigtail to both trigger and feed power to the switched side of the fuel pump relay in the RF fuse panel. By doing this, you eliminate one of the fuses in the circuit. Now you only use the Coyote ECU for triggering and powering the relay on the RF fuse panel. You still need that relay to be able to tie in the inertia switch (via negative trigger). I went with this option, which required cutting 2 wires on the RF fuse panel fuel pump relay (both the trigger and the power feed), then I repurposed the RF 12V IGN feed going to the fuel pump relay to power my seat heaters instead.

Tied both these to the Coyote pigtail (green Fuel Pump Relay Out) to supply power & trigger relay coil

Tied these two together

• orange = IGN feed busbar
• Tan = fuse input

*this supplies power to the fuse from the IGN busbar

Clipped this BATT feed going to the fuel pump fuse and capped the feed side

After cutting, I ran this end to the seat heaters connections (will provide power and coil trigger for the seat heater relays)

I cut the red battery feed wire here (this originally sent power through the fuel pump fuse, then over to the fuel pump relay switched input power)

Fuel pump 15A fuse (BATT circuit)

Relay device power input

Fuel pump relay coil positive trigger

Relay device power output (to fuel pump via rear harness)

Fuel pump relay coil negative (to inertia switch then to chassis ground)

MAIN RF CHASSIS HARNESS FUSE PANEL

COOLING FAN CIRCUIT

NOTES:

• NOT CURRENTLY USED
• Has an available relay & available 30A fuse

MAIN RF CHASSIS HARNESS COOLING FAN CIRCUIT

Currently unused (batt feed 30A fused + relay)

30A fuse

Blue wire from 30A fuse output is clipped & capped

Cooling fan relay

DK GRN-FAN THERMAO SWITCH in Sender Unit Harness & Front Harness is the relay coil (-)…either one can trigger the relay

• Clip here and attach your own negative trigger (or clip behind dash somewhere)

BATTERY FD – supplies relay coil + and also relay device power feed

Relay device power out

Relay device power in (BATT FED)

Relay coil (+)

AVAILABLE CIRCUIT w/ relay + 30A fuse

Blue wire clipped & capped 🡪 connect here if you want to use this circuit + relay

CLIPPED & CAPPED

FUEL PUMP CIRCUIT

NOTES:

• Fuel pump relay in RF fuse panel is being utilized by Coyote green wire (already fused in Coyote fuse box)
• Already has fuse in Coyote fuse panel, so not using the 15A fuse in RF fuse panel (repurposed this fuse for seat heaters)

MAIN RF CHASSIS HARNESS FUSE PANEL

Fuel Pump Relay

Fuel pump relay

Relay device power input

Fuel pump relay coil positive trigger

Relay device power output (to fuel pump via rear harness)

Fuel pump relay coil negative (to inertia switch then to chassis ground)

Relay power source (for device power & trigger) comes from green wire on Coyote pigtail

‘65 Mustang Ignition w/ RF harness

1 - Batter Feed (in) - yellow pigtail (FFR harness RED-IGN SW-->SOL and RED-HDLT SW 1 FEED)

�2 - Start (out) - blue/red pigtail (FFR harness LT BLU-EFI CRANK POWER and LT BLU-IGN SW-->NS SW)

�3 - Ignition On/Run (out) - orange/green pigtail wire (FFR harness ORG-IGN FEED->IGN SW)

�4 - Acc Feed (out) - no pigtail connection (FFR harness BRN-ACC FEED-->IGN SW and BRN-ALTERNATOR IGN)

‘65 MUSTANG IGNITION SWITCH WIRING

CUSTOM

BILLET BUTTON WIRING

https://www.custombilletbuttons.com/wiring-diagram/

• LEDs can be driven by separate white or black LED power wire, OR by the device power in (purple) 🡪 by connecting the orange wire (output of switch) to the LED power input (white or black wire)
• To select LED color, tie the LED negative wire to ground (wire color matches LED color)
• Can tie multiple to make mixed color
• Horn switch is momentary, footbox blower and hazard are latching

BILLET BUTTON WIRING

WIRE COLORS:

• Purple wire: +12V switched power in
• Yellow wire: normally closed (i.e. tied to purple when button is NOT depressed) – +12V device power out, non-switched
• Orange wire: normally open (i.e. tied to purple when button is pressed) – switched device power out
• Red wire: red LED ground
• Blue wire: blue LED ground
• Green wire: green LED ground
• White or Black wire: LED common anode (+) source --> use either parking light (to illuminate LED when headlights are on) OR tie to purple wire if you want it activated by same power source (when button pushed)

Add manual switch to inertia switch

Add SPST switch

NOTES:

• Add SPST switch (included w/ FFR kit) in-line w/ the inertia switch, which is just tied to ground. The inertia switch is the ground path for the fuel pump relay, so if you flip this switch, it acts as either a fuel shut off (if you are ever in an accident and the inertia switch doesn’t trip), OR you can use it as an anti-theft mechanism if you hide the switch under the dash
• Can put the switch before OR after the inertia switch so long as it is in series
• May want to extend the ground wires 🡪 place the inertia switch wherever you want (can be on DS or PS) but make sure it is accessible while the dash is in place in case you ever need to reset it.

New switch added to circuit

FUEL PUMP SHUTOFF VIA

IN-LINE MANUAL SWITCH (*can be security measure)

CUSTOM

HEADLIGHT FUNCTION

Source: https://thefactoryfiveforum.com/showthread.php?45818-White-quot-Dash-Light-quot-wire-no-power&p=523348&viewfull=1#post523348

• Using stock FFR headlight switch
• This diagram shows what it happening internally within the switch

HEADLIGHT SWITCH

86

85

30

87

Chassis GND

Add relay (activated by negative trigger from hdlt sw)

COURTESY LIGHTS

RED-COURTESY LT

NOTES:

• RF harness is normally supposed to activate the courtesy lights when the headlight switch grounds the circuit (i.e. the courtesy lights always have battery power, just no ground connection. Turning the headlight switch to courtesy light position just grounds the circuit (via GRY-TO HDLT SW wire getting connected to ground internally inside the headlight switch).
• When I wired my courtesy lights, I provided local chassis grounds (by splitting grounds off the harness ground wires), and +12V BATT FEED power from RED-COURTESY LT wire. With my setup, this would have left the courtesy light LEDs on ALWAYS with no way to shut off except battery cutoff switch
• So because of my mistake, to fix this, I added a relay to control the +12V RED-COURTESY LT feed to the LEDs but use the headlight switch circuit to trigger the relay - (GRY-TO HDLT SW) – this is a negative trigger on the coil of the relay. This will then allow the switched device power side of the relay to close and provide +12V BATT FEED from RED-COURTESY LT to power the LEDs

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COURTESY LIGHT CIRCUIT

CUSTOM

TURN SIGNALS & HIGH BEAM (IDIT MODULE) + Russ Thompson Turn Signal:

NOTES:

• Source: https://thefactoryfiveforum.com/showthread.php?44022-Russ-Thompson-Turn-Signal-and-IDIDIT-Relay-wiring-schematic
• +12V power tied directly to Blue Seas +12V battery busbar on inside of firewall

FUNCTION:

• When headlights are off, pushing button on RT turn signal stalk will flash high beams
• When headlights are ON, pushing button on RT turn signal stalk will switch between Hi/Low beam

Function w/ Russ Thompson Turn Signal:

• Source: https://thefactoryfiveforum.com/showthread.php?44022-Russ-Thompson-Turn-Signal-and-IDIDIT-Relay-wiring-schematic
• When headlights are off, pushing button on RT turn signal stalk will flash high beams
• When headlights are ON, pushing button on RT turn signal stalk will switch between Hi/Low beam

86

85

30

87

GND

Billet button LED

Billet button switch

Add relay (activated by billet button switch)

Diodes (5A/60V) to prevent back-feed to button LED

Relay output to L & R turn signals

HAZARD BILLET BUTTON

NOTES: I USED THIS OPTION

• Use billet button instead of DPST hazard switch
• +12V pink hazard wire (batt feed) powers the relay trigger, relay power, and billet button LED 🡪 this is a pulsing feed from the flasher in the RF fuse panel
• I branched off the PNK-HAXARD FLASHER wire behind the dash (before it gets to dash harness) to send it over to relay pin 30
• When switch is depressed, billet button LED flashes with hazards, and relay trigger & power also pulses w/ flashers

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ALTERNATE (no flashing button):

• One variation to this design would be to put the billet button on the ground side of the relay. Then you would need to provide separate +12V BATT FEED to the button LED, and tie the negative side of the LED to the button terminal (the ground side)
• Downside of this setup: when you push the button, the billet button LED won’t flash w/ the hazard lights (it will be fully illuminated while the button is latched)

86

85

30

87

Billet button switch

PNK-HAZARD FLASHER

(BATT FEED)

+12V BATT FEED

(ex: RED-RADIO MEM)

Billet button LED

ALTERNATE

(no flashing LED on button)

DASH HARNESS - HAZARDS

CUSTOM

Billet Switch Wiring:

• Purple wire connected to PNK-HAZARD FLASHER wire from RF dash harness
• White wire & Orange tied together 🡪 so LED gets power from flasher pink wire in RF harness when switch is acivated
• Red LED wire (-) is tied to ground
• Orange wire to relay pin 86 (+ coil trigger)
• Green, blue, yellow not used

White LED

(+) wire

RED LED

(-) wire

Orange wire

Purple wire

HORN BILLET BUTTON

BRN-HORN SW

(from horn relay coil ground)

BLK-GROUND

(tied to chassis GND)

Billet horn button LED

PARK LT FD

(turned on at headlight switch)

(+)

(-)

NOTES:

• With this setup, the horn button lights up ONLY when headlights are on
• The horn button just closes the horn relay coil circuit to ground (i.e. negative trigger)
• If we want the billet button to illuminate at night, we need to tie the button LED to the parking lights so they come on when headlights are on.
• The billet button LED feed should be tied to parking light fd. Can get this from 3 places:
• new branch directly off headlight switch terminal #4 (this gets a +12v feed when parking lights are on)
• tap into TAN-RT PARK LT FD wire or TAN-TAIL LT FD (can tap from main RF harness or in front or rear harness)
• Ground side of the button LED should get tied to BLK-GROUND (should be OK to daisy chain from ground terminal inside button or to any ground source) 🡪 this is always grounded. LED only turns on when PARK LT FD is activated (via headlight switch)
• When horn button is pressed, it triggers the Horn Relay Coil (via ground trigger) which then sends power through the relay device power to the horn

DASH HARNESS 🡪 HORN BUTTON

CUSTOM

Billet Switch Wiring:

• White wire 🡪 connected to parking light wire (from headlight switch) 🡪 LED illuminates when headlights are on
• Blue wire connected to ground (blue LED when headlights are on)
• Purple wire connected to brown horn switch
• Orange wire connected to black horn wire
• Yellow, Green, Red wires not used

‘65 Wiper Switch (Rotary)

‘65 MUSTANG SWITCH POSITION (verified)

In each position, this is what is connected (confirmed via multi-meter probing)

OFF:

D🡨🡪E (+12V IGN 🡨🡪 Motor +12V)

A 🡨🡪 G (Park 🡨🡪 LOW)

B 🡨🡪 C (Park 🡨🡪 HIGH)

LOW:

D 🡨🡪 C 🡨🡪 G (+12V IGN 🡨🡪 HIGH 🡨🡪 LOW)

A 🡨🡪 B (PARK 🡨🡪 PARK)

HIGH:

D 🡨🡪 C (+12V IGN 🡨🡪 HIGH)

A 🡨🡪 B (PARK 🡨🡪 PARK)

PURP-WIPER wire

From FFR fuse panel

PURPLE WIPER WIRE (+12V IGN)

NOTES:

• 10A fused ACC FED circuit from RF main fuse panel
• I replaced the Lucas L-35927 toggle switch provided with the FFR wiper kit with ‘65 Mustang C5ZZ-17A553-D rotary switch
• Forum post asking questions HERE
• At 12V, low speed uses 1.5A, and high speed it uses 2A
• Park connects to “Low” when in OFF position (internally in switch)

FOOTBOX FAN BILLET BUTTON

NOTES:

• Using ORG-EFI OR COIL (15A fuse, IGN FEED) wire
• Blowers each use max 2.5A, so 5A total on the circuit if both are in use
• Button illuminates when blower is powered ON
• Want IGN feed because don’t want to accidentally leave on and drain battery
• Split this feed to two separate relays to control each blower, and OK to use it for the relay coil positive trigger and device power input, then use each blower switch on the dash to negative trigger the relay

DS blower switch

PS blower switch

PS blower relay

DS blower relay

PS blower

DS blower

(+)

(-)

(+)

(-)

GND

GND

Button

LED

Button

LED

CUSTOM

ORG-EFI OR COIL

Billet Switch Wiring:

• Purple wire goes to DS blower relay pin 86 (+ coil trigger)….coil circuit grounded when switch is pressed (goes through blue LED)
• Blue LED wire (-) is tied to ground
• Power feeds: added diodes to both so current can only go one way (into the switch/LED)
• Orange wire connected to LED black (+) wire with diode to allow current flow from orange to black only (so switched power can power the LED)
• Also feeding black LED (+) wire with parking lights wire using diode to allow current flow from parking wire to black LED wire (so cannot back-feed parking lights from fan blower power)
• Yellow, green, red wires not used

FOOTBOX FAN BILLET BUTTON

DS blower relay

DS Blower Fan

(+)

(-)

GND

+12V IGN

15A Fuse

BLUE LED CATHODE WIRE

BLACK COMMON ANODE WIRE (for LEDs)

NOT USED

NOT USED

NOT USED

COMMON

+12V PARKING LIGHT

DIODE

DIODE

NO

NC

*INVESTIGATING* 🡪 Made this diagram to send to Billet Buttons to see if I have this wired up correctly.

Result:

• Suggested fix from F500guy on forum
• Thread discussing my issue

​

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DIODE

Diode prevents the blower power feed from accidentally turning on the parking lights

Diode prevents power generated from the fan free spinning from the wind (when not powered on) from back-feeding and lighting up the LED

Diode prevents the parking light feed from turning on the blower

Maradyne Fan PWM Controller

• https://thefactoryfiveforum.com/showthread.php?34158-!-Two-stage-cooling-fan-controller-for-Gen-2-Coyote-(will-work-for-any-engine)-115&p=435082&viewfull=1#post435082
• I used the 2nd diagram from the link (fan power from Coyote ECU orange wire, fan shuts off when engine shuts off)
• Fan PWM is controlled via the fan ground wire (to the Maradyne controller)
• I got +12V IGN feed from RF Harness ORG EFI or COIL wire (also used for DS/PS footbox blowers)
• Maradyne LED status:
• RED LED (top) – ignition power turned on
• GREEN LED (middle) – fan powered at low speed
• ORANGE LED (bottom) – Fan running at high speed

MARADYNE RADIATOR FAN PWM CONTROLLER

Gen 2 ECU

Fan power

(14ga orange wire)

Maradyne Fan PWM Controller

White 14ga

( - )

( + )

GND

Black 14ga

Blue

Temperature Probe

Orange

Yellow

+12V Keyed IGN

(RF Harness orange Coil/EFI)

Fan

Black

Dash indicator lamp

+12V speed/clock memory

DIODE

No connect

GND

UPDATED 6/29/2025

HEATED SEATS BUTTON (HI/LOW/OFF)

NOTES:

• Using original 15A fused fuel pump circuit in RF fuse panel (but not fuel pump relay)
• Powered off +12V IGN busbar on fuse panel so you don’t accidentally leave seat heaters running after shutting off the car and drain battery
• Wired jumper from +12V IGN busbar to 15A fuel pump fuse & using that for seat heaters
• Added new white wire from fuse output to go behind dash 🡪 branch this into both relays that came with the seat heaters to power the relay power and relay trigger
• Seat heater relays use the white wire (+12V IGN FEED) to power the relay coil & device power. Then the seat heater switch (DPST) negative triggers the relay coil to activate device power.

​

New WHITE WIRE behind dash for both seat heaters – 15A fused

IGN FEED busbar

15A fuse output to seat heaters via white wire in dash

Jumper IGN FEED to 15A fuse input

CUSTOM – using original fuel pump fused 15A circuit (but not original fuel pump relay)

Connect to GND behind dash

Connect to GND behind dash

White wire behind dash going to fuse panel (15A)

White wire behind dash going to fuse panel (15A)

New WHITE WIRE added from fuel pump 15A fuse

New WHITE WIRE added from fuel pump 15A fuse

Key w/ Push Button Start

(NOT USING)

NOTES:

• Not planning to add push-button start…I like having a key for this vehicle
• Source: weendoggy’s diagram https://thefactoryfiveforum.com/showthread.php?50379-Key-Start-and-push-button-diagram
• In this schematic, the key must be in the IGN position and the push button must be pressed to start the car
• If worried about button failure and want a backup, you could connect the “SOL” terminal from the key switch in parallel to the button. This means you could still turn the key to the START position and it would send 12V direct from the key switch to the clutch safety switch and then to the relay coil 🡪 this would activate the relay (w/ the key in START) and send 12v battery to actual Starter Solenoid – shown as the purple dashed line. This keeps the clutch safety switch in series (good for safety reasons).

MANUAL FAN OVERRIDE SWITCH

(NOT USING)

NOTES:

• For those using the Maradyne PWM fan controller, this is probably not necessary. They indicate they are happy with it….and don’t ever use the manual switch.