RDR 3000GT/Stealth Fuel Pump Rewiring

These instructions apply to a 1995 Mitsubishi 3000GT VR-4, but are easily transferable to any year of AWD 3000GT or Dodge Stealth.

Background Information

The Procedure - Part I: Stepping Up Input Voltage

Remove Airbox (or Air Filter)
  You'll need to remove your airbox or air filter (if you have a K&N) to access the fuel pump relay.


Access OEM Fuel Pump Relay
  Remove your fuel pump relay from under the fusebox bracket. It's directly under the fusebox and should have plenty of slack in the wiring to pull it out as shown in the picture. The rubber cover with the bracket attached just slides off of the relay.


Examine Harness-side of Relay
  Look at the side of the relay with the wires coming out of it. Note which wires come out of which holes in the harness. You might want to orient the harness how it is shown in the circuit diagrams so it's easier to figure out which wire goes where. In this orientation, Pin #1 is in the upper left (black wire with red stripe), and pin #5 is in the lower right (black wire with light blue stripe).


Remove Electrical Tape and Wiring Loom
  Carefully remove (you may need to cut) the electrical tape from the wires that attach to the relay. Pull back the wiring loom a little so you can access the wire loop between pins 3 and 5 on the harness. The wire will be black with a light blue stripe (B-L, by Mitsu convention).


Cut Wire Loop
  Cut the wire loop that connects pins 3 and 5. Again, this should be a black wire with a light blue stripe.


Attach Crimp Connectors
  You now need to prepare the freshly-cut ends of the [former] wire loop for connection to the new parts of the circuit.

To make thing easier, I suggest you use crimp-style connectors on the ends of your wires as this makes it a little easier to install things and it definitely makes removing things easier. I typically use insulated quick-disconnect connectors because they provide a secure connection and disconnect fairly easily. Also, if you use one male and one female connector for the wires here, you can return the circuit to stock very easily.


Prepare Relay For Connection
  Again, I suggest you use insulated quick-disconnect crimp-on connectors on the ends of your wires to make things easier. You'll also want to tie up the center wire of the relay harness (pin 87a) so it's out of the way. Further, you can remove it from the harness completely if you like (as shown in the next picture). To remove it, insert a pick or small probe into the side of the harness that the relay plugs into and push back the little tab on the connector - then it just slides out.


Examine Relay Pins and Wire Colors
  Take a good look at the colors of the wires on your wiring harness and which wire goes to which relay pin. The relay pins should be labeled on the bottom of the relay (as shown in picture), but your wires may be different colors than the ones in the pictures. That bears repeating: Look closely at the colors of the wires in your particular harness as they may not be the same colors as the harness in this picture.


Closeup of Wires In My Harness


Tape Up Relay and Harness
  Wrap up the relay and harness connections with electrical tape to prevent water or contaminants from getting into the relay connections.


Connect Relay Wires
  Following the circuit diagram, connect the relay as required. For the relay coil terminal that is to be grounded, a good place for this is the bolt for the airbox (or air filter bracket) as shown in the picture.


Alternate View of Connections
  You can see both relay coil connections (pins 85 and 86) and the fuel pump power connection (pin 87) here. Pin 30 of the relay (battery power) is not yet connected.


New Relay Connected To OEM Relay
  Again, you can see the relay connections... the red wire in the picture is connected to pin 30 of the relay, and it must eventually be connected to the battery through a fuse.


Wrap Up the Wires
  Using some wiring loom and/or electrical tape, protect the wires that go to the new relay.


Connect Battery Wire
  Connect a large wire (at least 14-ga) to the wire that goes to pin 30 of the new relay. This picture also shows the 4 connections to the new relay. The thin black wire is my ground wire for the relay coil. The thick red wire is my wire that goes to the battery. The other 2 wires go to the OEM relay as shown in the picture.


More Wiring Loom and Tape
  Again, you want to protect the wires from abrasion, heat, and moisture by wrapping them in wiring loom and/or electrical tape.


Secure the New Relay
  I chose to mount the new relay to the side of the fusebox near the DS IC hose. I had to slightly enlarge the hole in the relay bracket with a 1/4" drill bit.


Mount Fuse Holder
  Find a place to mount your fuse holder - here's one example.


Connect Fuse Holder and Install Fuse
  Install the fuse and complete the connection. One end of the fuse holder gets connected to the pin 30 relay wire and the other end of the fuse holder gets connected to the battery's positive terminal.


Disconnect Negative Terminal Of Battery
  Disconnect the negative terminal of your battery so you can safely disconnect the positive terminal.


Connect Wire to Positive Terminal
  Disconnect the positive terminal of your battery so you can connect the other end of the wire coming out of your fuse older to the battery. Use a ring terminal or other appropriate connector for this end of the wire. Reconnect the positive terminal to the battery.


Reconnect Negative Terminal Of Battery


Reinstall Air Filter and Start Car
  Put the air filter or airbox back on and start the car. Make sure it runs. If you're going to do the optional step below, you can continue after you make sure you have everything right so far. If you're not going to do the optional steps below, then you're done - go out and drive!


The Procedure - Part II: Reducing Voltage Losses With Larger Wiring

Access Wiring Harness for Fuel Pump Resistor
  It's located on the bracket for your fusebox and has only 2 wires. The resistor is the shiny silver thing with the heat sink in the lower left of the picture. Disconnect the chassis-side of the connector.


Access Fuel Pump Resistor Wires
  The large harness is the ABS pump harness, which is under your fuse box. Disconnect the ABS harness and pull back the wires as shown in the picture. You may have to disconnect some wire ties to get this much slack in the wires. Towel in place for ' clarity in the pictures.


Remove Electrical Tape
  Pull back the electrical tape and plastic wire protector to expose the wires for the fuel pump resistor.


Cut Resistor Wire and Create Wire Splice
  Cut the (B)lack wire with the (L)ight blue stripe and put quick-disconnect terminals on it. Using a male/female pair will allow you to quickly return the wiring to stock. Create a wire "T" from some 14ga or larger wire as shown in the picture. The trunk of this "T" should have the appropriate connector such that the end of the new wire (red in picture) can be connected to it.


Connect New Wire
  As shown in the picture, connect the new (red in picture) wire to the existing fuel pump resistor wire.


Button Everything Back Up
  Protect the new wire and its connection with electrical tape and/or wiring loom. Reconnect the wiring harnesses for the fuel pump resistor and the ABS pump.


Reinstall Air Filter or Airbox
  You're done in the engine bay, so reinstall the air filter.


Route New Wire to the Trunk
  The new wire you connected in the engine bay needs to make its way to the trunk. There are many ways to do this, so this is at your personal discretion. There is a stock gromet/hole near the brake booster on the driver's side and there's space to shove a wire through the existing wiring harness hole down behind the battery. You can also drill a new hole through the firewall.


Remove Spare Tire and RHS Cargo Tray
  The cargo tray on the passenger's side is held in by 3 screws - remove them and the tray, along with the spare tire, to access the fuel pump access pannel..


Remove and Modify Fuel Pump Access Panel
  The fuel pump access panel is held on by 4 screws. Remove the panel and bend the area where you intend to run the new wire to the pump so that there is clearance for the wire. I found that placing a large-diameter bolt wrapped in a towel under the panel and then beating on the panel with a rubber mallet worked ok. See picture for details.


Connect New Wire to Fuel Pump
  I'd already made a mess of the fuel pump wiring harness when I was previously experimenting, so please pardon the mess. You'll want to splice into the (B)lack wire with the (L)ight blue stripe located at pin #3 of the fuel pump harness. This is where the new wire should be attached.


Reinstall Fuel Pump Access Panel
  Put the panel back on, making sure that it doesn't pinch the new wire. I put wiring loom around the new wire to make sure it wouldn't get pinched by anything.


Replace Spare Tire and RHS Cargo Tray


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Last Modified Tue Jun 24 2003 12:31:01 PDT