The fuel pump kill switch wiring diagram above will show you how to convert any universal automotive relay to do the task. At the wiring you need to find the 12v supply wire from the ecu to the fuel pump.
Toyota Rav4 Service Manual Fuel Pump Control Circuit
Fuel pump switch wiring. You want to limit voltage drop by using a heavy gauge wire. In my experience wiring the electric fuel pump thru an oil pressure switch is done to shut off the pump in case of an accident where the ignition switch is still on but the engine is not running. The old gearhead way of doing it didnt include the oil pressure switch. Turning dash mounted toggle switch on energizes relay which in turn supplies electrical current from your battery through the circuit breaker to the fuel pump. No power on either side of switch. It shows the elements of the circuit as streamlined shapes and the power as well as signal links in between the gadgets.
For the electric fuel pump application the relay actuating switch will be a common three prong oil pressure switch that screws into a 18 27 npt oil pressure port on the engine. So use a larger gauge wire for lower voltage drop. Once that wire has been found cut that wire so that you now have half of that wiring running to the fuel pump and the other half running to the factory ecu. Tartruck nov 24 2011 share post 15. Fuel pump wiring for the red circuit is generally going to carry a much higher current than the relay. Gm used a simple.
I wired one into my truck and am pleased with the ease of installation and having the extra safety feature. Using a relay circuit to turn on your fuel pump provides maximum efficiency and reliability in fuel pump operation. The steps of re wiring your fuel pump are to first get to your fuel pumps wiring. I think the fuel pump is wired through the oil pressure switch like the new fuel injected cars have. Completing your kill switch install will allow you to turn off your fuel pump at any time. If you are putting your fuel pump kill switch together using a standard single post automotive relay the fuel pump kill switch wiring diagram below can help you.
An electric pump isnt usually wired to the acc ignition switch terminal but the on terminal thus the pump is powered during cranking anyway. As another alternative ron francis makes a fuel pump wiring kit that includes a relay and a collision shut off safety switch. I ran my relay trigger wires from fuel pump in trunk to one side of a battery switch under dash and ran the big blue holley fuel pump wire from harness to the other side of switch. I initially thought the holley blue wire would bring 12v to. This is a mandated safety feature on new vehicles so that the fuel pump cannot run after the engine dies in a crash or rollover. Variety of electric fuel pump relay wiring diagram.
A wiring diagram is a simplified standard photographic depiction of an electrical circuit. For big pumps try 12 gauge for smaller smaller 14 gauge.
Gallery of Fuel Pump Switch Wiring
