Q: Why don’t the connectors on your harness match my original Oxygen Sensors from my Donor Vehicle?

A: There were over 10 different connectors used by GM for Oxygen Sensors over the run of the LS engine applications.  It is impossible for us to match everyone’s Oxygen Sensor connectors, there are just too many variations.  Also, there are two different types of Oxygen Sensors.  So we install the connectors on our harness that we KNOW will be compatible.  Here is a short Youtube Video Explaining this!

Q: Do I have to have my PCM/ECM tuned to use a standalone harness?

A: Yes.  All standalone LS and LT swaps will have to have the PCM/ECM tuned to remove VATS and all other non-used items that are programmed in from the factory.  There are NO EXCEPTIONS to this rule.

Q:  Does your harness come with an OBD II (DLC Port, Diagnostic Port)?

A: Yes.  All BP Automotive standalone harnesses come with an OBD II Port.

Q: Does your harness come with a fuse block and relays?

A: Yes.  All BP Automotive standalone harnesses come with a fuse block with two relays included.  The two relays are for Ignition Power and your Fuel Pump.  Our fuse block also comes with a cover and is labeled with a legend inside the cover.  Just like an OEM vehicle.  No chasing down your instructions for a legend.

Q: Does your harness have fuel pump wiring?

A: Yes. All BP Automotive harnesses have a 10-foot length of 14ga wire that is the power supply for your fuel pump.  You will ground the other wire from your fuel pump to the chassis.  Our harness also has a fuel pump relay included.

If you are using a high-performance pump that the manufacturer recommends running a 10ga wire for you will need to utilize a fuel pump hot wire kit.  This only applies to high-performance pumps such as an Aeromotive. 

This does NOT apply to a Walbro 255lph pump that is commonly used on LS and LT Swaps.  The 14ga wire included in our harness is more than adequate for these types of pumps.

Q: How long is your harness?

A: All BP Automotive standalone harnesses are 5-foot or 60 inches from the back passenger side of the intake manifold.  This is usually more than enough to accommodate almost all customers’ mounting needs.  Our harness also includes a high quality sliding Aptiv (Formerly Delphi) grommet to seal your firewall if you decide to mount your PCM/ECM inside the passenger compartment.

Q: Does your harness come with a grommet?

A:  All BP Automotive standalone and our 1993-2002 F-Body direct fit harnesses come with a new Aptiv (formerly Delphi) grommet.  Our standalone harnesses use a sliding grommet so that it can be positioned for your individual needs.

On our direct-fit F-Body harnesses the grommet is an exact OEM replacement and is taped into the factory location.  This grommet will fit perfectly into your original hole in your firewall!

Q:  What hole size do I need to drill for the grommet?

A:  All BP Automotive standalone harnesses will come with a grommet that slides and can be placed in the firewall at any place on the main trunk line of our standalone harness.  Per page 2 of your installation manual, this hole needs to be 2 1/8th inch in diameter.

Q: Does your harness come with cooling fan relays or provisions for cooling fans?

A:  No.  Our stand-alone harnesses do not include the cooling fan relays themselves.  However, all BP Automotive standalone harnesses come with two fan relay control wires.  These wires will go to your relays and the PCM/ECM will control the cooling fan relays according to temperature and AC Pressure.  Some PCM/ECM will have to have the fan temperatures and AC pressures tuned in.

If you purchased a direct fit harness from us for an F-Body or an S-10 all of the wiring will be included, and on the S-10 Harness fan relays will be included

Q:  I am using a 4L60e what year does it need to be to use it with my LS Swap?

A: If you are using a 4L60e transmission that did not come with the LS Engine that you are swapping you will want to ensure that it is 1996 or newer electronically.  Some 1994 and 1995 transmissions can be updated to 1996 electronics.  Check with your local transmission shop to see if you can.  We cannot help with updating a transmission, you will have to speak to a transmission builder.

Q:  I am using a 4L80e what year does it need to be to use it with my LS Swap?

A: If you are using a 4L80e transmission that did not come with the LS Engine that you are swapping you will want to ensure that it is 1996 or newer electronically.  Some 1994 and 1995 transmissions can be updated to 1996 electronics.  Check with your local transmission shop to see if you can.  We cannot help with updating a transmission, you will have to speak to a transmission builder.

Q:  I am installing a BP Automotive Standalone Harness, where is a good place to get the 12v switched ignition?

A:  While it is impossible to give an exact answer for every application, the best place to find an ignition source that is hot in RUN AND CRANK is to connect it directly to the ignition switch.  Do NOT jumper wires or terminals at your ignition switch to try and achieve voltage in RUN AND CRANK.  This can cause a very unsafe condition.

Another common location to find switched ignition power is the wire that used to power the ignition coil with the old engine that was in the vehicle that you are swapping the LS engine into.

These are just examples, and they should be able to help you find a source for switched ignition.  If you are having trouble finding a source, we suggest enlisting the help of a friend to turn the key into the different positions while you check with a multimeter for 12 VDC.

Q: I have a 1997-1998 LS1 PCM, can BP Automotive build a harness for this PCM?

A: The 1997-1998 LS1 PCM is prone to failure and has become rare and expensive as a result.  Moreover, these PCMs have their own pinout and BP Automotive does not build harnesses to utilize the 1997-1998 PCM.  We recommend upgrading to the 1999-2000 09354896 or the 2001-2002 12200411 PCM.  These PCMs are far more common, and much more reliable.