We also have another fan harness with no fan connectors so you can connect to Flex-a-Lite, SPAL, etc. This makes for easy, Hassle Free hook-ups right out of the box. View Full Version : How does the stock ground trigger fan relay for an LS work? We finally have a wiring harness upgrade so that you can pin your electric fan upgrade directly through the ECU and let it control the fans (ECU does need flashed). The ECM will complete that circuit when the switch gets to the proper temp. The Flex-a-fit® radiators made by Flex-a-lite feature dual-pass design with the inlet and outlet on the passenger side tank. One of the most challenging parts of installing an LS engine is finding the correct radiator hoses. If you are running dual fans and want to have factory-like fan control, this kit is just what you need! to use twin fans, about 12 inches in diameter, staggered high and low. The fan (s) are triggered via a temperature switch and 40-amp relay combination. If you have A/C you will want to confirm if the A/C command input on the ECM will turn on the fans once the compressor starts running. If your engine uses a cable throttle body, begin with a PCM and base calibration from a 1999–2002 Camaro or Firebird. Simply hanging a fan against the back of the radiator core is not advised. The fan control wire is fused/relayed and can connect directly to your Fan using 10 gauge wire (minimum size)." A complete installation instruction booklet is included with every module. Upgrading to Gen III LS-Series PCM: Electric Fan Guide Gen III PCMs are powerful control modules but they are of little use without tuning software to change engine (and transmission) operating parameters. In GM LS applications GM used three relays to control your fans in series to enable the fans to work together. Don’t worry though, it is designed not to hang too far below the crossmember of your car. The PCM is sending a ground signal to the relay but the relay is not activating. The ECM is using a relay, and energizes the relay when it detects a certain temperature. - LT1 - LS1 - 05+OEM - Flex-a-Lite - Universal - Street & Strip - We have you covered. 2003-2006 Silverado, Sierra, Tahoe, Suburban, and Yukon (DBC ONLY). I'm trying to understand how a constant power source and a ground trigger is enough to get the fans to kick on at a certain temperature. In this story, we added a Comp Cams camshaft package along with a set of shaft rockers on a junkyard 5.3-liter engine and dynoed it … Silverado, Tahoe, or ? Made in the USA. A short time ago, we did an article on Edel b rock’s Pro-Flo 4 EFI system. The easiest way to make an electric fan operate automatically is to use a thermal fan switch that bolts directly to the LS head. In GM LS applications GM used three relays to control your fans in series to enable the fans to work together. Look at the picture to compare to your fan connector. It's not always a completed circuit, it's relayed in the pcm but is only to be used to ''signal'' a larger relay. In many cases, if you’re putting MegaSquirt on a car that came with an LS motor, we recommend installing the MegaSquirt in parallel with the stock ECU if you want these features to keep operating. No dyno, no tuner, no factory re-flashed ECU! LS wiring harnesses and swap kits for all Gen III and IV engines. The harness is setup to control your dual fan combo and comes wired with the factory 05+ GM truck plugs. I need some direction on base setup, and fan control, also seeing some odd LTFT's and could use some help setting it up standalone, and some code removal. We wanted to see exactly how cheap we could swap an LS into an older full-size GM car for and what other items needed to be considered during the swap. :). Looking for an Affordable, In Stock, Plug and Play wiring harness for your LS Swap? Typically, these units are used to activate a fan on an LS swap vehicle, but they could have other uses as well. Before getting too far into a discussion of electric fans and PCM calibrations, it … https://www.lsenginediy.com/upgrading-gen-iii-ls-series-pcm-electric-fan-guide Available for most popular LS swap applications, these radiators are constructed entirely of aluminum for exceptional weight savings over stock equipment. Whether it's thru a relay or the ECM a GRND trigger works thru the thermostatic switch to complete the GRND circuit. Control is set to turn on a 12 V fan at 100 Deg C (212 Deg F) coolant temperature. We decided to simplify it with a Painless Performance Products LS1 swap … Champion Cooling Systems Dual Pass Radiators are a perfect choice for your LS conversion vehicle. Gen V 2010-2019 Camaro Fan LT Swap PWM Fan Harness, 1999-2006 Silverado Sierra Tahoe Suburban Yukon Fan Harness for GM Fans, Gen V 2014-2018 GM Truck/SUV LT Swap PWM Fan Harness, 1999-2002 Silverado Sierra Yukon Tahoe Suburban A/C Update Kit, Gen III (24X) Stand Alone Harnesses, Kits, and PCMs, Gen IV (58x) Stand Alone Harnesses, Kits, and ECM/TCM, Gen V Stand Alone Harnesses, Kits, and ECM/TCM, Gen III DBC (24x) EV6 Injectors (Flex Fuel/Gen 4), Gen III DBC (24x) Vortec TRUCK/SUV Multec Injectors, Gen III DBW (24x) EV6 Injectors (Flex Fuel/Gen 4), Can be used in universal applications when not using a BP Automotive Harness, Weather Resistant, Factory Style Underhood System, Made In The USA at Our Facility in Kentucky. This task is greatly simplified, The specific LS engine you choose to start with will depend mostly on the budget you have to work with. and we have a harness for 2005-12 GM Truck fans. Not sure about the fan output responding to the sensor independent of the compressor output control state. Select an option... 1999-2002 Silverado, Sierra, Tahoe, Suburban, and Yukon. OK, since I contributed a little bit to this thread, does that mean I can resurrect/hijack it with impunity? On many LS powered cars, the factory engine control unit does a lot more than controlling the engine. PSI sells Standalone Wiring Harnesses for GM Gen II, III, IV, & V LS/LT based engines and transmissions. From propelling the LS-, Coyote-, and Gen 3 Hemi-swap trends, to continuously innovating late-model and vintage vehicle performance, Holley’s commitment to its customers and their cars is at the core of everything we do. When I measure voltage at the relay I get 12v on both sides of the coil. Also included is an easy-to-follow wiring diagram. Even with 12V at the fan there is no flow without a GRND. Control is set to turn on a 12 V fan at 100 Deg C (212 Deg F) coolant temperature. Hello, New to HPTuners, but loving it. That includes fans from the LS1, LT1, 350 TPI. A proper shroud allows air flow from the entire core to reach the fans. No Trying to find a wiring diagram to look at is kinda hard without that. Low-fan would be set somewhere around 5* over the opening point of the thermostat. All Be Cool LS Swap Modules contain a ''vehicle specific'' Be Cool Radiator, Shrouded Electric Fan(s), Fan Brackets with Hardware, ''Easy to Use'' Wiring Harness with 40 AMP Relay(s) and Sending Unit, Billet Recovery Tank w/Cap, and to top it off a Be Cool Signature Billet Cap. This is better than just running two relays that turn the fans on individually at high speed because it is less inrush current on your electrical system. I am working on a LS swap and I cannot get the cooling fans to work. LS engines use a … I would say it a bit differently: the ECM grounds the coil circuit in the relay (86 to 85, with 85 going to the ECM) which allows power to flow (30 to 87) to the fan motor. Our first step for the swap was figuring out what LS engine to go with. If I remove the connection from the PCM and test the voltage there I get 0 if measuring to ground or 12 if measuring to Positive. An “LS swap” is an engine switch and installation. Motor - LS1, 04 GTO 6 speed, setup standalone in a drift car. Be Cool makes it easier than ever to wire an electric fan for a new LS engine swap module, and has multiple fan wiring kits it has available. The “LS” can mean any engine made by GM from a factory truck 4.8 to GM’s popular LS3 or LS7. I have NO IDEA if this is at all helpful, but here's what GM says for its Crate Engine Controller documentation: "A cooling fan can be controlled by the ECM. What's the exact 2008 platform this swap came from? With this kit both fans will turn on low speed together when the low-speed relay control is triggered, then when the high-speed relay control is triggered both fans … No more sticking a temp bulb through the radiator. Also how to enable the fans in HP Tuners when using a truck harness. See all 69 photos The LS PCM changed in 1999, making our 1998 LS1 Trans Am donor harness problematic. If your engine uses an electronic throttle body, begin with a PCM and ba… Only logged in customers who have purchased this product may leave a review. How does the stock ground trigger fan relay for an LS work. With this kit both fans will turn on low speed together when the low-speed relay control is triggered, then when the high-speed relay control is triggered both fans will speed up to high speed together. Of most importance is the consideration of electric fan control. The PCM calibration is specific to each of these implementations. The FiTech 70051 Ultimate LS Standalone EFI ECU kit is the ultimate LS swap computer for DIY enthusiasts who want full control over their engine and transmission. We use these to supply ground to either the fan or fan relay, … I have seen one that worked that way but that doesn't mean all do. The harness is 4.5 feet long from red positive connector to the end of the fan connector. Startup guaranteed. Optional fan connectors can be added for a plug and play connection to 1993-2002 LT1/LS1 F-Body OEM fan assemblies. And an LS swap will make all of our acceleration problems a thing of the past. The pan has the capacity of seven-quarts and is six-inches deep. The fan control wire is fused/relayed and can connect directly to your Fan using 10 gauge wire (minimum size).". This is the new harness that many customers have been asking about. Dec 22, 2014 - #car #fan #control #relay #kit #efi #conversion #kit http://www.psiconversion.com/tech_articles.html# I would like to use the PCM for fan control as it seems it would be less wiring and less cost, but I just can't figure out how this works. Avoid having to buy additional software programs, learning how to think in computer code, or relying on a questionable 3rd party tuner. If given a choice I'd use the ECM/PCM commanded output. If your project uses electric fans, begin with a PCM calibration from a vehicle that has electric fans. From propelling the LS-, Coyote-, and Gen 3 Hemi-swap trends, to continuously innovating late-model and vintage vehicle performance, Holley’s commitment to its customers and their cars is at the core of everything we do. Getting to the bottom of what it takes to wire your swaps fuel pump and fans. THANK YOU to all that stuck with us during this hectic time. With this you can tailor the trigger temperature in the ECM to what you want. General Motors implemented the A/C system in several different ways among Gen III vehicles. The PCM would send a signal (via ground?) Often there are Low and Hi-temp on circuits for dual fan use. The GM LS and LT lines of V8 engines are perfect for engine swaps, and now, Speartech is offering a way to make the LS V8 or LT V8 swap even easier. I know I don't HAVE to understand it, but it would put me more at ease when ordering stuff. All the items listed below are things you will need to consider, research, and plan on having when doing an LS swap. Looking for an Affordable, In Stock, Plug and Play wiring harness for your LS Swap? We are currently up … Flex-a-lite® now has a line of performance aluminum radiators specifically for LS engine swaps in popular muscle cars, trucks and Jeeps. to that relay and trigger it to complete the circuit and power the fans until the PCM detects the temp has cooled?Pretty close. We have moved! 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