Holley EFI
Wiring an Electric Cooling Fan - Holley EFI
1st, Enable the Electric Fan(s) in "Basic I/O" - "System Parameters".
2nd, Enter "Inputs/Outputs" (also in System Parameters), and select the "Output Type" for Electric Fan(s).
I prefer it to be a ground output, however, it can be programmed to be either one (+12V or ground).
3rd, It must be Pin-Mapped to an available J1 connector output pin; click "View Outputs" on the Pin Map.
Then click & drag it to an available J1 Connector pin. Now you can run this wire to your electric fan relay.
A relay must be used because all the ECU's Outputs are rated at a maximum of 2 amps.
You're actually programming the ECU to assign a specific function to that pin/circuit. It doesn't have a specific
assigned pin; it's any available Output pin, according to which Output Type you selected in Inputs/Outputs
screen (System ICF). Don't worry, the EFI software won't allow you to make a mistake with the Pin Map.
https://www.holley.com/document/tech...9r10545rev.pdf (Pin Map Instructions)
To connect up to 4 Inputs & Outputs to the EFI Main Harness, use I/O Auxiliary Harness 558-400.
Eight Wire I/O Auxiliary Harness Connector Pin-Out (also in the Holley EFI Wiring Manual - LINK):
Pin A...A12...White/Blue (Input #1) F,5,2,T,H,G
Pin B...A3....White/Red (Input #2) F,5,2,T,H,G
Pin C...A13...White/Black (Input #3) F,5,G
Pin D...A4....White/Green (Input #4) F,5,G
Pin E...B12...Gray/Yellow (Output #1) H,P+
Pin F...B11...Gray/Red (Output #2) H,P+
Pin G...B10...Gray/Black (Output #3) G,P−
Pin H...B3....Gray/Green (Output #4) G,P−
http://documents.holley.com/199r10516.pdf (Holley 558-400 I/O Auxiliary Harness Instructions)
The 558-400 I/O Auxiliary Harness is 20 feet long, and it's "plug & play" into the EFI main harness.
If you want more options, you don't have to use the preexisting Electric Fans output in "Basic I/O" - System Parameters.
I created a custom Electric Fan Output because I don't like the fans running (hot engine) when I have the key-on/engine-off.
I configured it to enable Above 650 RPM, and with a 190°F Activation - 185°F Secondary Deactivation (Hysteresis Mode).
Other criteria can be programmed too; such as adding a third Sensor Input Trigger (>95% TPS) to deactivate it at WOT.
Some Holley EFI users with a VSS, program the electric fans to deactivate above a certain (MPH) road speed. I chose not to.
If you created electric fan Outputs in the Inputs/Outputs ICF (not the System ICF), then nothing is programmed in Basic I/O.
http://forums.holley.com/showthread....8389#post58389 (How To Create A Custom Input/Output)
https://forums.holley.com/showthread...3586#post63586 (2 Speed Electric Fan Control Information)
If the I/O menu icon (ICF) isn't already uploaded (added) to the top Toolbar, follow these instructions:
(This same procedure applies to all the various Individual Configuration menu icons/items.)
The "I/O" function is an "Individual Configuration" of the Holley EFI software.
At top of screen, Click "Toolbox" and "Add Individual Config".
At top of new window, select "Individual Configuration Library".
At bottom of new window, select "Holley EFI Inputs/Outputs Config".
Select "I/O" and open "Base Config - Blank.io".
The "I/O" icon will then be present at top of screen.
After creating the new Input, "Pin Map" it to an available ECU connector input pin.
Terminator EFI users also have two ECU Electric Fan Outputs.
Originally Posted by Danny Cabral
The Holley HP ECU does have two programmable "PWM+" & "PWM−" Outputs (or two 12V & ground switched Outputs and four Inputs).
However, all these Outputs are limited to 2 amps, so an appropriate electronic (solid state) controller is necessary for PWM control.
A PWM electronic controller is required, to convert the PWM signal (from the ECU), into variable voltage to the electrical component.
Contact the manufacturer of your electric motor (fuel pump, water pump, cooling fan, etc.) for the recommended frequency.
Also, be sure your electric pump or fan is capable of pulse width modulation. Not all electric motors are capable of PWM.
First, create the custom Output(s) in the I/O ICF. Name it, select PWM+ or PWM−, Enable & Configure it.
Open PWM Setup. Select "Fixed" Type, "Duty Cycle %" Table Units, and enter the Frequency.
Configure which two ECU parameters (X & Y axis) you'd like to control the PWM Output Table.
Then "Pin Map" this new Output to an available J1 pin/connector (see "View Outputs"), and run this wire to the PWM relay/controller.
UPDATE: See post #32 for Pulse Width Modulated electric cooling fan control details.
FYI: Holley's 554-111 High Current Relay (device/solenoid driver) is not for use as a continuous duty pulsing relay.
It's rated at 40 amps and can operate at 100% duty cycle continuously or temporarily pulsing (PWM) high currents.
http://documents.holley.com/199r11304.pdf (NOS 15620NOS Solid State Relay Instructions - See Page 2)
The Holley ECUs already has two existing Electric Fan Outputs (not PWM) in Basic I/O - System Parameters.
The ECU provides a ground output to trigger an electric fan relay.
Read section 11.0 (page 14) & section 26.1.1 (page 25) of the owner's manual:
http://documents.holley.com/199r10653rev10.pdf (Terminator EFI Manual)
The 3-wire mating I/O Harness is already included with the Terminator EFI system.
http://documents.holley.com/199r10704.pdf (Holley 558-420 Terminator EFI Remaining I/O Kit)
• If anyone needs an electric fan relay/wiring kit, this Holley kit works with C950, Avenger, HP & Dominator ECUs:
https://www.holley.com/products/fuel.../parts/534-134 (Electric Fan Relay/Wiring Kit)
http://documents.holley.com/199r10158rev.pdf (Relay/Wiring Kit Instructions)
https://www.holley.com/products/fuel...s/parts/40100G (Mr. Gasket 40100G Sealed 30/40 Amp Relay Kit)
These instructions illustrate the C950 ECU control, but it's the same for Avenger, HP & Dominator ECUs.
https://www.holley.com/products/cool...ds/parts/FB403 (Frostbite Electric Fan Relay/Wiring Kit)
http://documents.holley.com/frostbit...structions.pdf (Frostbite Relay/Wiring Kit Instructions)
You won't need the included sensor for ECU fan control, but this kit has a sealed relay for the same price.
• Electric Fan #1/#2 relay terminals (ECU ground signal scenario):
#85 - Ground signal from ECU Output.
#86 - Fused +12V power to relay coil.
#30 - Fused +12V power to relay contact.
#87 - +12V power to electric fan.
#87A - Not used in this application.
Terminals #30 & #87 can be reversed.
http://www.autoshop101.com/forms/hweb2.pdf (Understanding Relays)
Electric Fan #1/#2 relay terminals (ECU +12V signal scenario):
#85 - Ground to relay coil.
#86 - +12V signal from ECU Output.
#30 - Fused +12V power to relay contact.
#87 - +12V power to electric fan.
#87A - Not used in this application.
Terminals #30 & #87 can be reversed.
http://www.autoshop101.com/forms/hweb2.pdf (Understanding Relays)
It's nothing special. Although for ECU wiring, a relay with a resistor or diode (across the coil) should be used.
It's a typical five terminal automotive relay (Bosch/Tyco) that can be obtained at your local auto parts store.
The first five relays listed below, are all the same five terminal SPDT configuration, with bracket & resistor:
Tyco V23234-A1001-X043
Bosch 0 332 209 161
Hella 87420
Pico 5591PT (Relay/Wiring Kit)
Echlin/Napa AR143 (Wiring Kit)
Echlin/Napa AR204 (50 amp, diode protected - correct wiring polarity required.)
If you don't want to concern yourself with the correct wiring polarity, just use a resistor type relay (no polarity wiring matters).
For diode relays, the relays have a schematic diagram on their side. Follow the directions below regardless of relay manufacturer:
+12V - Anode
Ground - Cathode
http://www.autoshop101.com/forms/hweb2.pdf (Diode vs. Resistor Relays - Page 12 & 13)
• I'm running the Spal dual 12" electric fans (with the integral mounting shroud). These electric fans cool very good (3168 CFM),
and this new curved blade design is a lot quieter than their previous straight blade design. They spike on at about 55 amps, and
run continuously at 39 amps. I use this heavy duty (a little larger than the typical 4-pin relay) Bosch 75 amp power relay
#0 332 002 156 with built-in diode protection (series & parallel diodes). I had already wired the circuit using heavy gauge wire
and with the addition of this relay, my electric fans have given me years of trouble free service. Spal specifies one 60 amp Maxi
fuse (LINK) with a single 75 amp relay (two 30 amp fuses if using two conventional relays). One Maxi fuse wire can be connected
directly onto a relay eyelet terminal (see image below). This is the absolute best electric cooling fan relay I've ever used:
https://www.waytekwire.com/item/7555...6-Power-Relay/ (Tyco 75 Amp Relay)
http://www.rockauto.com/en/parts/bos...wer+relay,3648 (Bosch 75 Amp Relay)
https://www.waytekwire.com/item/3800...le-Connector-/ (Optional Mating Connector)
http://www.theelectricaldepot.com/pdf/pwr%20relay2.pdf (Dimensional Drawing)
http://www.littelfuse.com/data/en/Data_Sheets/299.pdf (Maxi Fuses)
I highly recommend this diode protected 75 amp relay, since it can protect your sensitive
electronic components such as ECUs, ignition modules/boxes, stereo equipment, etc.
This is an excerpt from Hella concerning diode protected relays:
Eliminating voltage spikes: Voltage spikes from 300V to 500V can occur momentarily when a relay is switched off.
Sensitive electronic equipment can be damaged or malfunctions can occur if these spikes reach the vehicle electrical
network without suppression. A relay with a resistor reduces these voltage spikes to less than 100 Volts. A relay with
a diode eliminates them completely. The correct polarity of the connections is marked on the diode protected relay.
• If incorporating a switch to manually override the ECU, you simply need a diode on the ECU's fan signal wire.
This is to prevent back-feeding voltage or ground (depending on the "Output Type" selected) into the ECU.
If incorporating a switch to manually disable the fans, no diode is required since the switch just opens the signal wire.
(Purpose built 4WD/off-road vehicles may manually turn the fans off before crossing deep water to prevent breakage.)
A diode is also required if the air conditioning is directly wired to activate the fan relay (single relay scenario).
I prefer to use a dedicated A/C relay, in addition to the existing fan relay, to activate the electric fan(s).
Shrink tube the installation. The relay trigger (coil) is very low amperage, so this diode works well:
https://www.radioshack.com/products/...nt=20332048261 (Radio Shack 2761144)
I like to use strong diodes, just so it isn't a weak link, harness-wise.
Some diodes are so flimsy, you can pull them apart with your fingers.
• The Holley V5 EFI software/ECU firmware finally added an A/C activated option for the electric fans. Check mark A/C "IAC Kick"
in the Holley EFI software (Basic I/O - System Parameters), select a +12V or Ground Input Type in Inputs/Outputs (still in the
System ICF), and Pin Map it to an available "H" (+12V) or "G" (Ground) Input Type pin. See below for more information.
http://documents.holley.com/techlibr...teoverview.pdf (Holley EFI V5 EFI Software Update Overview - Pages 7 & 8)
Originally Posted by Holley EFI V5 EFI Software Update Overview
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