Red Line Harness Modification
Blue Chip Diesel FMS & Redline MAP Harness Modification
FOR 1998-2000 TRUCKS: MOD FOR FMS AND REDLINE
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Remove our harness from the factory harness and the sensor.
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Cut AND SAVE the phone cord from our MAP harness, keeping it as long as possible, and discard the rest. In a Dodge, cut the GREEN wire ("signal wire" if doing a Ford or Freightliner) in the FACTORY harness, where you can connect three wires from the phone cord conveniently.
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Hold the clear plastic plug of the phone cord so you are looking at the side WITHOUT the latch, with the wire going DOWN from the plug.
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If you see the wires in the plug on the phone cord are BLACK, RED, GREEN and YELLOW from left to right, attach the RED wire in the phone plug cable to the previously cut GREEN wire ("signal wire" if doing a Ford or Freightliner) that comes from the sensor plug, and connect the GREEN wire in the phone cord to the other end of the previously cut wire that comes from the factory harness. Connect the BLACK wire from the phone plug cable to the BLACK ("ground" wire in a Ford or Freightliner) wire in the factory harness. The YELLOW wire in the phone cable is not used.
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If the wires in the plug are YELLOW,GREEN,RED and BLACK from left to right, attach the GREEN wire in the phone plug cable to the previously cut GREEN wire ("signal wire" if doing a Ford or Freightliner) that comes from the sensor plug, and connect the RED wire in the phone cord to the other end of the previously cut wire that comes from the factory harness. Connect the YELLOW wire from the phone plug cable to the BLACK wire ("ground" wire in a Ford or Freightliner) in the factory harness. The BLACK wire in the phone cable is not used.
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We strongly suggest soldering and using shrink tubing to make the connections, but if you have to use crimp connectors, please be sure they are positioned so the wires shouldn't break over time and are as weatherproof as possible. Plug in the sensor plug and plug the phone plug into our box BEFORE turning the key on, to prevent setting a 237 code. Phew, you are done!
FOR 2001-2002 TRUCKS: MOD FOR FMS AND REDLINE
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Remove our harness from the factory harness and the sensor.
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Cut AND SAVE the phone cord from our MAP harness, keeping it as long as possible, and discard the rest.
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In a Dodge, cut the GREY OR GREY WITH RED TRACER wire ("signal wire" if doing a Ford or Freightliner) in the FACTORY harness, fairly near the plug, where you can connect three wires from the phone cord conveniently.
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Hold the clear plastic plug of the phone cord so you are looking at the side WITHOUT the latch, with the wire going DOWN from the plug.
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If you see the wires in the plug on the phone cord are BLACK, RED, GREEN and YELLOW from left to right, attach the RED wire in the phone plug cable to the previously cut GREY OR GREY WITH RED TRACER wire ("signal wire" if doing a Ford or Freightliner) that comes from the sensor plug, and connect the GREEN wire in the phone cord to the other end of the previously cut wire that comes from the factory harness. Connect the BLACK wire from the phone plug cable to the BLACK wire ("ground" wire in a Ford or Freightliner) in the factory harness. The YELLOW wire in the phone cable is not used.
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If the wires in the plug are YELLOW,GREEN,RED and BLACK from left to right, attach the GREEN wire in the phone plug cable to the previously cut GREY OR GREY WITH RED TRACER wire ("signal wire" if doing a Ford or Freightliner) that comes from the sensor plug, and connect the RED wire in the phone cord to the other end of the previously cut wire that comes from the factory harness. Connect the YELLOW wire from the phone plug cable to the BLACK wire ("ground" wire in a Ford or Freightliner) in the factory harness. The BLACK wire in the phone cable is not used.
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We strongly suggest soldering and using shrink tubing to make the connections, but if you have to use crimp connectors, please be sure they are positioned so the wires shouldn't break over time and are as weatherproof as possible. Plug in the sensor plug and plug the phone plug into our box BEFORE turning the key on, to prevent setting a 237 code. Phew, you are done!
HOW TO MAKE A “FORD OR FREIGHTLINER ONLY” VP44 MAP HARNESS WITH A FOUR WIRE PHONE CORD UPDATED 12/14/17
As the plug for one end of the MAP harness that we make is virtually unavailable and frightfully expensive if and when we can find them, we are offering a free solution. This modification is not as perfect as the plug in harness is, because if you ever have to disconnect the phone plug from our box and drive the truck, you will have to connect the two ends of the signal wire that you cut in the factory harness to make the ECM get the right voltages. If you don't connect them it will cause a drivability problem, and set a low map voltage code. It is not unusual to intermittently see this code appear right after startup when using this mod, but it won't cause any drivability issue, and the light on the dash will go out after a few key starts.
We strongly suggest soldering and using shrink tubing in this install or mod to make the connections, but if you have to use crimp connectors, please be sure they are positioned so the wires shouldn't break over time and are as weatherproof as possible.
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Be sure that the sensor is plugged into the factory harness when looking for voltages to determine wire function. Find the "signal wire", ground wire and power wire in the FACTORY HARNESS coming out of the MAP sensor, as follows: With the ignition key in the "ON" position and engine NOT running, look for the wire coming out of the sensor that should have either .5 (1/2) or 1.0 volt in it. A 1998 -2000 should be .5 (1/2) volt. A 2001-2002 should be 1.0 volt. This wire is the “signal” wire and the one to cut where connections will be the easiest.
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One wire in the harness should have 5 volts. Don't connect anything there.
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The wire that has 0 volts with the key on, is the ground wire. Do NOT cut this wire but do connect a wire from the phone plug cable to it as indicated below. Because the connector on the phone cord can be crimped onto the cable two opposite ways, which screws up color coding, follow this procedure. Hold the clear plastic plug of the phone plug cable so you are looking at the side WITHOUT the latch, with the wires going DOWN from the plug.
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IF THE WIRES IN THE PLUG ARE BLACK, RED, GREEN and YELLOW from left to right
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Connect the RED wire from the phone harness to the previously cut "signal" wire that comes from the SENSOR PLUG.
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Connect the GREEN wire from the phone harness to the previously cut "signal" wire that comes from the TRUCK HARNESS.
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Connect the BLACK wire from the phone cord to the “ground” wire in the FACTORY harness. Do not cut the wire in the FACTORY harness. Just strip a small spot and connect there.
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The YELLOW wire in the phone cord is not used.
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IF THE WIRES IN THE PLUG ARE YELLOW, GREEN, RED and BLACK from left to right,
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Connect the GREEN wire from the phone harness to the previously cut "signal" wire that comes from the SENSOR PLUG.
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Connect the RED wire from the phone harness to the previously cut "signal" wire that comes from the TRUCK HARNESS.
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Connect the YELLOW wire from the phone cord to the “ground” wire in the FACTORY harness. Do not cut the wire in the FACTORY harness. Just strip a small spot and connect there.
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The BLACK wire in phone cord is not used
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AFTER CONNECTING THE THREE PHONE CORD WIRES, plug in the factory truck harness plug into the MAP sensor and plug the phone cable plug into our box BEFORE turning the key on. You’re done!