Frequently Asked Questions

Our dealers purchase in large volume and they are able to pass along savings that we cannot do on individual sales. We as the manufacturer, can't undersell our dealers. All of our dealers set their own pricing and that might be lower than the suggested retail price. You can get your specific part application information from us, and then buy the part from one of our dealers. No matter where you buy your Painless Performance harness, you'll still get direct Painless Performance Tech Help. To purchase a harness, we will refer you to a dealer close to you, or you can check out our web page dealer list.

"Battery Positive" or the power feed from the battery.

Voltmeters are much easier to install. Ammeters require large gauge wire and most older ammeters don't have enough amperage range to operate safely with modern high-output alternators. A voltmeter is hooked up as easily as a light bulb, and gives a very accurate indication of your charging system condition. 

The only wire in a Painless kit that is connected to a one-wire alternator is the "alternator B+" wire. It connects to the main post on the back of the alternator. The "alternator exciter" wire or "ALT IGN B+" wire is not connected.

Some cars and trucks need a complete bumper to bumper wiring harness replacement, but the supply of new harnesses for that vehicle may have run out long ago. If the connectors to your various switches and sockets are in good shape, they can be reused on the ends of a new 12 or 18-circuit harness from us. You mount the new blade-style fuse block, route the attached wiring to the various components, and terminate the ends. If you've done an engine swap or installed aftermarket gauges, the Painless harness can adapt these things to your vehicle at that time. If you can't find a New Old Stock Replacement harness for your Chevy, Plymouth, Triumph, Apollo, or almost anything else, our universal harness can be installed and you'll be on the road.

Check the catalog for specific vehicle applications. If your car or truck is not in the catalog, you will need to use one of our "universal" kits. 

1. Decide if you need 12 or 18 circuits. If you are just wiring the basic functions, stick with the 12 Circuit kit. If you are planning to add power windows, door locks and other creature comforts, the 18 Circuit kit is the one to go with.
2. Is your ignition switch on the column or the dash? Use the kits designated "for GM Steering Column" for the later style "keyed" steering columns from GM.

We have people installing our harnesses every day that have never done any wiring before. There are many variables, but with our instructions and a factory wire diagram, we tell people they can expect to spend about 20 hours installing our universal harnesses. If you have questions or need information, our tech line is available for help Monday through Friday 8-5 Central time at 817-244-6898.

In some cases, the word "universal" brings up the vision of a square peg in a round hole. A Painless harness is a long way from the old glass fuse blocks and cheap wire you used to buy at the auto parts store. A 12 or 18-circuit Painless Performance harness is universal in that it can be adapted to almost anything and made to look factory.

You can insulate the bare wire ends and store them back in the harness for use later, or if you are absolutely sure you'll never need the wires, you can remove them from the harness.

Yes, part numbers 30020 (12 Circuit) and 30021 (18 Circuit) are exactly that.  Think of our 10101 or 10201 with out the fuseblocks.

Yes, 30001 (12 Circuit) and 30003 (18 Circuit) are fuseblock only parts.  Normally, if a fuse block is in such bad condition that it needs replacement, the wire harness needs replacement also. Unless your original wire harness is in great condition, and you have good diagrams telling you where each wire connects, it's easier just to replace it all. Sometimes it takes longer to adapt a harness to a new fuse block than it does just to replace everything.

Use either our 12-circuit 10120 or our 18-circuit 10220 "Trunk-mount" harness. The kit is designed so the fuse block can be mounted behind the seat or even in the trunk of most cars. The kits will work with both GM keyed-column and other ignition switches. Click here to check out these harnesses. 

Before our FI harnesses are shipped, every single harness is plugged into a board that tests every wire in the harness. If there are any problems, they will show up on our board, and not later on your car. 

Our TBI, TPI, and LT1 harnesses are designed for specific computers, relays and sensors. We use a list of common FI parts that we know will work together. The combinations of parts on our lists work. The parts you have may not. There is a list in every F/I instruction book.

Yes and no.  If you are referring to the fuel injection part of your wiring project then you will only need an additional harness if your vehicle must pass emissions testing.  See our fuel injection harness matrix for these mating emission harnesses.  If you are referring to the chassis side of your wiring project such as lights, dash and steering column then yes you will need a chassis wiring harness along with your Painless fuel injection harness.  Our harnesses are what are referred to as stand alone harnesses. They include a ALDL diagnostic connector and Check Engine Light. They are designed so you can take a TBI, TPI, LT-1, LS, GEN III & IV series engine and transmission, and our harness, and put them in anything. They are not designed for a specific vehicle. Any engine compartment wiring other than the fuel injection itself, such as dash gauge wiring and sensors would have to be provided, or reused, on the vehicle once the system is installed in.

The standard length harnesses are designed to mount the PCM under the dash or in the right hand kick panel. The distance from the back of the intake manifold to the PCM connectors is 4 feet. The extra length harnesses have a total of 8 feet of wire between the back of the intake manifold and PCM connectors. This allows for the PCM to be mounted under or behind the front seat or behind the headlight buckets if desired. 

A complete list of compatible parts for the harnesses we sell is available in every instruction book.  Search our website for the Painless part you are looking for (a pdf. version of the instruction manual will show on search results page and is free to download.)  All of your parts may or may not work if you got them all off of the same vehicle, but these lists will help you if you don't have all the parts needed. You can also see how the parts interchange between types of systems.With these lists you save money by only buying the parts you need.

General Motors introduced this system into their vehicles in 1990 and still use it as a vehicle deterrent.  If the engine and factory PCM from one of these VATS equipped vehicles is transplanted from the donor vehicle into another vehicle such as a hot rod or sand rail, this VATS system must be defeated.  There are three types of VATS General Motors uses.  Year and application of all types of VATS are listed below.  Please note that each Painless Performance VATS module is designed to work with specific PCMs and that these PCMs cannot have Corvette programming as Corvettes have the serial VATS type of anti-theft deterrent system.

Early VATS:  1990-1992 late tuned port fuel injection from Camaros/Firebirds and Corvettes.  With this VATS use the Painless Performance part number 64023 module.  This module works with Camaro programmed PCMs with serial numbers; 1227730, 16198262, 88999196.

Late VATS:  1992-1997 early and late LT1s from Camaros/Firebirds, Corvettes, Roadmasters, Impalas, Caprices and 1997-2002 LS1s from Camaros/Firebirds, GTOs, and Corvettes.  With this VATS use the Painless Performance part number 64024 module.  This module works with Camaro programmed PCMs with serial numbers; 16159278, 88999183, 16197427, 16188051, 88961150, 16238212, 1220411, 9354896.

Serial VATS:  PCMs from Corvettes and late model GM pickups have what is called serial VATS.  Painless Performance VATS modules will not defeat this system.  In order to run a PCM with Corvette or pickup programming you must have the serial VATS programmed out of it. 

Watch the "Check Engine" light. If it stays off, or goes off when the ignition is in the "start" position, the pink/black wire needs to be moved to another power source. This wire must be hot in the start and in the run position or the car may never start. We suggest using the coil feed circuit. 

Put the fuel filter on the pressure side of the fuel pump. Fuel is what lubricates and cools the pump. When the filter plugs up, the the pump is starved for fuel. If the filter is put in front of the pump, the pump has to not only push the fuel to the injectors, it has to pull the fuel through the filter. 

Tune Port Fuel Injection- KOEO 40-47psi

                                          KOER 30-40psi

Throttle Body Fuel Injection 9-13 psi

CMFI  60-62psi

Gen3 Truck KOEO 55-62psi

LT1  KOEO 41-47psi

            w/regulator vacuum applied 3-10psi less than KOEO

LS1  KOEO 55-60psi

LS2  KOEO 55-60psi

LS7  KOEO 55-60psi

Ford 5.0HO KOEO 35-45psi

                     KOER 30-40psi

KOEO= Key On Engine Off

KOER= Key On Engine Run

Does the PCM need a VSS signal to operate correctly?  Generally speaking the answer to this is yes.  The PCM uses the vehicle speed sensor to determine what gear to command the transmission into when an automatic is equipped.  The VSS also lets the PCM know when the vehicle is not moving or coming to a stop.  Without this signal the engine may idle very low or even stall.  Painless Performance suggests always using a vehicle speed sensor.

When a late model engine is transplanted into a project car, the PCM will sometimes need to be reprogrammed.  Listed below are some of the parameters inside the PCM that may or may not need adjustments or deletions.  Please note that TBI, TPI and early LT1 PCMs use removable chips.  These chips are what will be reprogrammed on these fuel injection systems.  With late LT1 and newer fuel injection systems the PCMs do not have removable chips. The internal flash memory is what is reprogrammed.

1. Vehicle Anti-Theft Systems (VATS) can be programmed out of any flash-able chip or PCM.  If you are not using one of the Painless Performance VATS delete modules, or you are using a PCM that uses serial VATS, the PCM must be re-flashed in order to delete the VATS.  If you do not defeat or delete the VATS the engine will start, run for two seconds and then die.
2. If you are using a PCM controlled transmission, the PCM must be flashed with the proper transmission drivers in order to control it.  For instance, if you plan on using a 4L60E transmission and an LS1 engine the PCM must be flashed for this setup.  You cannot use a PCM flashed for a T-56 six speed and run a 4L60E transmission with it.  Also, keep in mind that the up-shift and down-shift points, line pressure, torque converter lock-up points and many other parameters can be altered when the PCM is flashed.
3. Throttle by wire engines must have the PCM flashed to work with the corresponding TAC module and throttle pedal.  You cannot take a PCM flashed for a cable throttle engine and run a throttle by wire setup.  This is also true for the reverse.  If using a throttle by wire setup, keep in mind the programmer can eliminate the traction control strategies that are factory programmed into the PCM.  Doing this will help with throttle response.
4. Timing, fuel, diagnostic trouble codes, emissions, electric cooling fan temps, speedometer corrections, speed limiters, and about 30 other parameters in your PCM can be modified by your programmer.  Do some research and ask around for a trust worthy programmer.  Make sure you figure out exactly what you want before you have the PCM flashed.

1997-2004 LS1/LS6 Corvettes have throttle by wire engines.  To transplant one of these engines into your project car use Painless Performance part number 60522 or 60523.  These harnesses will operate T-56 standard or 4L60E/4L65E transmissions.  Please see the harnesses instruction manual for the parts needed for this transplant.

In 2005 General Motors moved away from the LS6 and made the LS2 standard equipment for the Corvettes.  All LS2s are throttle by wire.  Painless Performance offers either the 60520 or the 60521 harness for this engine transplant.  These harnesses will operate the throttle by wire system, T-56 standard transmissions and 4L60E/4L65E transmissions.  Note: these harnesses use a 2002-03 LS6 PCM (serial number 12200411), pedal and TAC module in order to operate the LS2 engine and its throttle by wire throttle body.  Engine production codes ZJA, ZJB, 5MC, YTA and 6MC work with these harnesses.  Any other LS2 engine production codes will need the crank and cam sensors and target wheels changed to be compatible with these harnesses.  Please see the harness instructions for other parts needed for the transplant.

In 2001 General Motors offered traction control on their trucks.  If the truck was ordered with traction control it also came with the throttle by wire system.  In 2003 throttle by wire systems became standard equipment for all trucks.  Painless Performance is currently working on designing a harness for this application.

Our Throttle Body, Tuned Port and 4.3L CMFI Fuel Injection harnesses use one O2 sensor.  Our LT1, LS1, LS2, Gen 3 truck and Vortec truck fuel injection harnesses use two O2 sensors.  We do not use the post Catalytic Converter O2 sensors on any of these harnesses.  Where applicable, you can purchase the optional add-on emissions harness which will include the wiring for post Catalytic Converter O2 sensors.

Painless builds stand alone harnesses.  These transplant harnesses do not need to be connected to the chassis wire harness of the vehicle receiving the transplanted engine.  They do not plug into the factory bulkheads of the vehicle the engine is transplanted into.