2ND fuel pump wiring help | AEM
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2ND fuel pump wiring help

I have a 2004 evo 8 and was wondering what pin number would be best to turn on my 2nd fuel pump at certain boost levels?
Also is there a wiring diagram for adding the relay?



AEM_BB's picture
Last seen: 1 year 6 months ago
Joined: 06/04/2014 - 11:53
You can use any spare pin

You can use any spare pin listed as a Low Side or Injector output which is not already being used. For instance, assuming you have a 30-6310 EMS, pin 6 is the EGR solenoid valve which is not used on the AEM EMS and is listed as "available" in the pinout. 

As far as wiring, it's no different than wiring anything else with a relay that uses a ground trigger. Below is an example. 85/86 are interchangeable, so are 30/87.

30: +12v power, preferably from battery with a suitable fuse and suitable gauge wiring

85: available lowside or injector output from EMS (pin 6 in above example)

86: +12v ignition power (NOT battery/permanent power)

87: +12v output to + side of pump with suitable gauge wiring

You'll then ground the pump negative to a good chassis ground.