Results 1 to 3 of 3

Thread: Sniper & A/C

  1. #1
    Join Date
    Jan 2018
    Holmen, WI

    Default Sniper & A/C

    I have not purchased SNIPER EFI yet, however, I'm well into reading the entire installation manual. I'm wondering how SNIPER works with A/C. Can it increase idle speed when A/C turns on? I believe I read of its ability to kill the A/C at WOT. I'm more interested in how it behaves with A/C in normal driving conditions. Would like to hear from those running SNIPER & A/C. Thanks! Shoebox

  2. #2
    Join Date
    Nov 2014
    Ont. Canada


    Download the Sniper EFI software and then you can see what it does.

  3. #3
    Join Date
    Dec 2009


    See the A/C IAC Kick function. Like the Terminator, HP & Dominator EFI, it's only a momentary increase in IAC.

    Are you looking for a momentary increase in IAC or a high idle function? The A/C "IAC Kick" function only produces a momentary increase in IAC, so the engine RPM doesn't dip down when the A/C is turned on (or in your case, electric fans). It works fine, but it does not increase & hold the idle RPM like a high idle function. Actually, the IAC Kick function is usually not necessary. It's typically a tuning issue with the Base Fuel Table. If you need a high idle function, it can be programmed in the EFI software Advanced ICF (1D Table, "Target Idle Speed Offset" Table Type, Switched Enable, A/C Kick Activation, Enabled) to use as a high idle switch.

    For more information about RPM dip/instability when electric fan(s) or A/C turns on: (Electric Cooling Fans Wiring Info)

    The Sniper EFI electric fan ground wires (pin C, light blue - Fan #1 & pin D, light green - Fan #2) trigger the relay coil − (terminal #85). Yes, terminal #85/Ground is the industry standard for good quality relays, with or without a diode. Sniper EFI instruction manual: LINK - page 17 & 50.
    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. (Understanding Relays)

    If your A/C compressor is ground activated, this works perfectly with the Sniper Input #1:
    See page 8, "10-Pin Connector": (Holley Sniper EFI Quick Start Manual)
    Converting A/C signal wire from +12V A/C compressor clutch wire to Sniper's negative A/C IAC Kick signal wire (Input #1) with a relay: (Sniper EFI A/C Compressor Signal Wiring Info)

    FYI: The A/C IAC Kick input must be used for the "Enable Fan #1 When A/C On" to function.
    Page 19, "Enable Fan #1 When A/C On": (Holley Sniper EFI Help Manual - EFI Software, Tuning & Datalogging)
    Then assign the A/C IAC Kick wire in the Sniper EFI software to Input #1.
    See page 8, "10-Pin Connector": (Holley Sniper EFI Quick Start Manual)

    If you're using the Holley EFI A/C Shutdown feature, it requires a relay for operation. It usually triggers a preexisting A/C WOT relay. (Addition Information - Read Post #2 & #10)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: Dominator MPFI & DIS, 100HP progressive dry direct-port NOS, A/C, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, 160A 3G alternator, Optima Red battery, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us