Xenocron Fuel Pump Relay Kit Instructions

***These are general instructions.  Take time to plan out this installation before you cut or install ANYTHING, as your installation may be different than the one outlined here.  Use of a voltmeter is recommended. Take note of the relay diagram below before you begin.***

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Parts included:

·         10ft of 10AWG red wire

·         2ft of 10AWG black wire

·         2 “eye hook” connectors

·         2 “spade” connectors

·         2 large crimp connectors

·         2 small crimp connectors

·         1 relay with harness





1.      Disconnect your battery. (usually the negative)

2.      Determine what power source you will be using for your fuel pump.  We recommend using either the positive terminal on your alternator or your battery.  Connect the large 10AWG red wire to this power source.  If applicable, use one of the included “eye hook” connectors.  Before connecting the other end of this wire, take note of whether you will need some of it to connect the fuel pump to the relay harness (see step 4).  If the relay and harness are mounted close to the pump, you may not need any additional wire.  You can now connect the other end of the 10AWG red wire to the thick black wire on the relay harness (pin #30) using one of the large crimp connectors.

3.      Cut off the plug on the end of the factory wiring to the fuel pump.  Connect the positive wire from the stock wiring to the small red wire on the relay harness (pin #85) using one of the small crimp connectors. Connect the negative wire from the stock wiring to the small black wire on the relay harness (pin # 86) using one of the small crimp connectors.  If you want to retain the factory connector without cutting it, use male spade crimp connectors (not included).

4.      Using the 10AWG black wire, you will now make a new ground for the pump.  On one end, crimp an “eye hook” connector onto the black wire and ground this to the chassis.  It is important you have a CLEAN chassis ground so you may need to ground down, paint or primer depending on your application.  Connect the other end of this black wire to your fuel pump negative.  Depending on your application, you may be able to use one of the included “spade connectors.”

5.      Reconnect your Battery

6.      To test (before hooking up the final wire to your fuel pump), most ECUs have a “priming” stage when you turn your key to the “ON” position.  Normally the pump will prime for 2 seconds and then shut off.  To test, hook a voltmeter up to the thick BLUE wire from the relay harness and see if you receive 12 volts when the ECU primes the pump.  If this is the case, you have hooked everything up correctly.  Hook up the BLUE wire to your Fuel Pump Positive terminal.

7.      Finally, connect the thick blue wire on the relay harness (pin # 87) to the positive terminal on the fuel pump.  Depending on your application, you may be able to use one of the supplied “spade connectors.” If you are mounting your relay far from the pump, you may need to extend the blue wire using some of the included 10AWG red wire and a large crimp connector.

Here is what you should see when you open the package:relayparts.jpg