Have power to fuel pump relay but no power at the inertia switch. HELP!!!
What kind of car/truck is it? Is the inertia switch in trunk?
If you have power before relay but none after the relay is bad.
The inertia switch can also get tripped by very hard bumps jolts etc and has to get reset if it does.
swapped out relay and made sure inertia switch was not tripped, still nothing
so you've checked for power before and after relay and inertia switch. Have you checked for power at the fuel pump (actual plug) or can you access it?
or are you just going by whether or not the fuel pump runs?
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SOURCE: I have a 99 tacoma with no power to fuel
Look to see if you have power at pin 1 of the circuit opening relay. The C.O. Relay is what powers the fuel pump. If you have power there (a blue wire), you have an open circuit between the relay and the pump.
SOURCE: where is the fuel pump relay on 1991 lincoln
the fuel pump is inside the gas tank, this is true on all Fords with electronic fuel injection
Engine Starts:
· Fuel Pump secondary circuit shorted to power
· Fuel pump relay contacts always closed
· Open in fuel pump monitor (FPM) circuit between ECU and connection to POWER TO PUMP circuit
· Heated Exhaust Gas Oxygen (HEGO) sensor shorted to power
· faulty ECU
Engine Does Not Start:
· Open inertia switch or inertia switch circuit
· Open in or between ECU and fuel pump (This includes open in fuel pump brushes/windings)
· faulty ground connection at fuel pump
The easiest way to check this circuit is to go to the fuel pump relay. If the relay clicks when the key is turned to the "RUN" position, then the inertia switch circuit is ok.
The Pink/Black wire starts from the fuel pump relay and goes two directions. One side goes back to the fuel pump. The other side is the fuel pump monitor circuit and goes to pin #8 at the ECU. This wire should only be hot for a second or two when the ignition is turned to the RUN position.
The fuel pump relay receives power on the Black/yellow wire. It comes from a fusible link at the power distribution center. This wire should be hot at all times.
If all the above is working as designed, them you probably have a bad fuel pump.
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