Wiring Harness InformationWWW.LT1SWAP.COMVisit mypage for a lot of New Pictures & Harness Guideschannel for How Tovideos - E-Mail:Here is some information for LT1, LS1, Vortec 4.8, 5.3, 6.0 wiring harnesses. Thereshould be enough here to get you going in the right direction. Some of these Ihave pictures of completed harnesses I have modified for easy installation.I have a lot of pictures so please be patient and let them load. If youfind this information useful, or have suggestion on something to add, I will try toget it done.
Reason for this being is simply because the LS engine is the best engine out there, blowing the competition away. We hope this information log on the LS engine gives you a full understanding of the line-up GM offers, so you can LS swap the world.
My goal isto help the hobbyist to be able to complete a harness transformation by themself. I would only hope you send the PCM to me when it comes time for it.I do not charge for ANY information.Thanks!-Brendan. Sample schematic similar to what you may see in the following pages.
This may help you to learn how to read the schematics1992 to 1997Includes: Camaro/Firebird, Corvette, Caprice/Impala, Roadmaster1996 to 19991999 to 2007 TONS OF INFO HERE, Please Readall the pages linked.2007 to 2009- New Harness Modification INFO added 11/6/2012!2010 to 98 to 2002 - New PCM Pinout info specific to 98, 99-02F-body. 3/30/2013- Wiring harness info specific to the 2004 GTO LS1- Adam will rework most LS1, Vortec Truck, and F-Body LT1 Harnesses- Purchase new harnesses for swaps, Vortec 4.3, 5.7, 7.4, LS, LT, Truck lots of applicationsTypical 'External' Connections.thisapplies to most any GM wiring harness.12v+ Battery Connection - The computer requires a batteryconstant connection. This is so the PCM can remember learned information aboutthe engine over time. This includes idle control, fuel trims, andtransmission adapts. Its very important that the battery hot wires(usually ORANGE) are hot all the time.Key 12v+ Connection. The PCM also gets 12V+ from a KEYHOT source. This is what 'powers up' the PCM.
Its important that this keyhot power, along with power to injectors, coils, and so on, STAY HOT whencranking over the engine. Some accessory positions on key switches ARE NOT HOTwhen cranking. This also includes older vehicles that had POINTS ignition.
Eventhe COIL wire on some of those went dead when cranking. This is because whencranking the coil was boosted to 12v+ through the R terminal on the startersolenoid. After cranking, power was restored to the coil through aresistor, lowering voltage to 6 volts.Fuel Pump Relay Control - The computer on GM fuelinjection systems is designed to control a fuel pump relay. The computerdoes this by supply a 12v+ (POSITIVE) signal to the relay. The signal isonly present for two seconds at key on.
Fuel pump operation resumes whencranking over. The PCM ONLY commands it back on when the PCM reads thatthe engine is turning over. So, if there is a condition where there is a badcrank sensor, fuel pump will come on, turn off, and will not turn on whencranking.Brake Switch Signal - For automatics with lock upconverter, the PCM needs signal when brake pedal is pressed. However, thesignal needed is opposite how you're brake lights work. The PCM wants 12v+constant on this wire when brake IS NOT pressed, and OPEN Circuit whenthe brake IS pressed. If you vehicle was equipped with a lockup trans tobegin with, you probably already have the proper normally closed switch mountedby your brake light switch. If you do not, you can use a relay to performthe same thing.
On most relays, there are 5 terminals, 2 of them turn the relayON when provided ground/power. There are then a normally open leg and anormally closed leg on the relay and a supply. By feeding 12v+ on thesupply leg, and hooking the Brake Switch Signal wire to the normally closed leg,you will now have the correct signal for the PCM. When the brake ispressed, 12v+ flows to brake lights, tap into this wire, and run it to the relayto turn the relay on.
This will cause the normally closed leg tobecome open, thus turning OFF the 12v+ signal to the PCM. When you releasethe brake pedal, the relay will turn OFF, and then feed 12v+ to the PCM.VSS Signal - This wire is a 4000 pulse per mile signalfrom the PCM used by some aftermarket speedometers. This can also be usefor the electric cruise control boxes used on early 90s GM cars & trucks.PCM can be programmed to match tire size and axle ratio for you're swap, so thissignal is calibrated. Chrysler/Jeep vehicles typically need a 8000pulse/mile signal to run the speedometer.TACH Signal - On 1993 LT1 withdistributors, this comes from the negative side of the coil. Later LT1 andon LS1, Vortec 4.8/5.3/6.0 this comes from the PCM, which generates this signal for aaftermarket tachometer.
The stock LS tach signal is 4 cylinder typesignal. This can be programmed as 4, 6, or 8 cylinder signal. Some 2003+LS PCM's tach signal is not strong enough, and needs boosted.Fan Controls 1,2 - GM PCM's typically will controlelectric fans, usually 2. The PCM will supply the (negative) or GROUND signal toturn on fan relays. YOU CAN NOT DIRECTLY CONNECT PCM FAN CONTROL WIRE TO FANS.YOU MUST USE A RELAY.How to wire up a fan relay.using a (negative) or GROUNDcontrol from PCMWire going to terminal 30 & 87 should be 10-12 gauge to handlethe current draw of the cooling fan. Terminals 85 & 86 can use 16-22 gaugejust fine. Relay coil draws less then 1 amp.
Make sure the ground for the cooling fan is a good one, alsoensure there is a good ground from the battery ( - ) side to the frame.Use this schematic to wire up a DUAL SPEED fan such as the Ford Taurus fan.This uses a 5 terminal relay for the on on the right in this schematic.When the HIGH speed kicks in, it removes power from the first relay. Thisprevents power from being applied to both wires of the fan at the same time.If you want your fan or fans to turn on with a/c compressor, you can use thefollowing wiring to do that. The label 'TO FAN RELAY CONTROL (-) cansplice into the wire from the PCM to the FAN relay. This way the PCM can stillcontrol the fan when A/C is off, or when A/C is commanded on, the fan comes onright away.Here are some pictures of a typical automotive relay that can befound at most parts stores.Contact InfoBrendan Patten7227 Private Road 1830West Plains MO 65775.
Common Electrical Problems in a HomeBelow are some of the most common electrical problems that happen in the wiring system of homes in the U.S. After each of the electrical problems I give an explanation or a resource from this or another website. For other problems or a more complete treatment of these, browse my mainpage.Problems With Light Bulbs and FixturesLight bulbs are burning out at a high rate. There can be various reasons for this, depending especially on how widespread the problem is in your home and whether the bulbs you buy are ideal for your situation.
See.Some lights are flickering or blinking. This represents asomewhere along the circuit. If the blink happens through much of the home, aconnection could be the one having the trouble.A recessed light (flush to the ceiling) goes off sometimes and later works again. This is probably its built-in safety 'cutout' keeping the light from overheating. It is telling you that the wrong style or wattage of bulb is being used or that ceiling-space insulation is too close around the light.Some lights get extra bright while others run dim. Bulbs may even be popping, and an electronic appliance or two may have died recently.
This is a condition that will continue to be destructive to equipment in you home. It is from aconnection (or a bad neutral that is shared by just).Dead Outlet ProblemsA set of outlets or lights simply went dead. If you have reset any breakers or GFCIs (do you know?), you are probably left with a poor connection somewhere along a circuit. So find theof this 'open.' Half of an outlet works, but the other half doesn't always work.
Even after years in your home, you may not be aware that one half may be energized by a wall switch. The other common cause is that use over time has loosened the hold that one half has on the cords you plug into it.Outlets have gone dead in bathrooms, garage, kitchen, or outdoors. The outlets in these particular areas have been required since the '70s or '80s to go dead by means of a('GFI' or 'GFCI'), when it senses a problem that might shock you. That one of these devices has tripped off is the most common reason those outlets go dead.Tripping-Breaker ProblemsA circuit breaker or outlet has tripped off and won't reset. Don't be tempted too easily to blame the breaker or GFI. It is probably responding to a condition elsewhere on the circuit it is protecting.
![Ls swap electrical issues troubleshooting Ls swap electrical issues troubleshooting](http://www.150tunes.com/images/harness.jpg)
To find what that is, see my.A circuit breaker often trips when the microwave or a hair dryer is used. If the tripping is not immediate, these high-wattage items (when running along with a few lights for awhile) are probably too much for the circuit.
If these 'overloads' can't be avoided by limiting the use of other things on the circuit, a new separate circuit for the heavy item is the only solution. Many hair dryers, however, have a lower-watt setting on them; using that might help.Common Electrical Problems With SwitchesA wall switch gets rather warm.
Dimming switches do this - it is normal for them when running 600 watts worth of bulbs (or less). Heat at a receptacle is another matter; a connection there needs immediate improvement.Two switches are supposed to control a set of lights but don't always work right. Occasionally a switch goes bad. More often this problem comes from someone havinga switch wrongly.A switch does not seem to control anything at all. If you are not the first owner of this home or if you replaced receptacles recently, switched receptacles may have been disabled by how they were replaced. This applies mainly to bedrooms and living rooms.
See.Other Home Electrical ProblemsOur new clothes dryer won't heat up - just like the old one wouldn't. Most likely there is a poor connection at the dryer's receptacle or at its circuit breaker. If you have a fusebox instead, one of the dryer's two fuses may be blown.Our electric bill seems to be quite a bit higher than normal. One culprit I have seen is a hot water pipe leaking. Even one drip at a time, significant money is leaking out of your wallet, assuming your water heater is electric.
But there are many other possibilities. See Michael Bluejay's page on.Most other common electrical problems, and uncommon as well, are dealt with at my mainpage.©2005-2018 Laurence Dimock.